What’s one of the best things of having an Android phone? Well, not to mention anything related to how it works and the different apps and features you can get without having to pay ridiculous over pricing is that you can have a ROM or firmware that works better than the original stock one.

This guide is instended for Galaxy S2 (which is the one I have, therefore the one I can speak about). Still, googling and searching in XDA forums might give you the answer for some other Android phones and the process shouldn’t be too far from this one for each other phone.

Now, of course this will void your guarantee but if you like me buy an International Unlocked version with no warranty, then it really worth to have a little risk in your life (because of course, if you do something wrong you might end bricking it!) and install a new ROM into it.

This will guide you on how to:

1)      Root your phone.

2)      Install CWM.

3)      Backup your current (stock) ROM.

4)      Install a new ROM in it.

I would say that each part of the process is really independent from the next one, and depending on what you need you might stop at each one. People might just need to root your phone, and that’s why this guide should be helpful for many people even though they might not be seeking to install a new ROM but only to root their phones or to do a backup.

Before we get our hands dirty, I would like to say: there is some risk in this operation, so unless you want to take the risk by yourself and not make me responsible for anything that happens to you phone, then stop right now. Again, many things can go wrong on this process and even though majority of people following these steps shouldn’t have any problems, you might end with a nice ‘brick’ valued in $550.00.

Now, if you are reading this new paragraph you want to continue, so let’s do it:

Previous steps before doing anything at all:

Before do anything in this process, you need to have the correct drivers for your Windows machine (sorry folks, this post is only for Windows machines). In order to safely do this, just download Samsung KIES software and install it. Connect your phone and the system will automatically install all drivers needed for your machine to ‘understand’ your phone. After that, I recommend using the same KIES to backup your phone contacts, tasks, calendar, etc, because at some point of the process you might need to wipe the entire phone, so you need to be able to get things back in your phone again.

Rooting your phone:

Ok, first thing you need to do is root your phone, which means that you will ‘unlock’ your phone to be able to take new ROMs and/or do more things than the regular stock firmware (or the manufacturer, in this case Samsung) would allow you to do. No, this is NOT related to unlocking you phone to work with different carriers, so don’t get me wrong.

You need to download the following file, which is called “GalaxyS2Root.zip”. This contains a .BAT file and it will connect to your phone (using the drivers you previously installed). Now, go ahead and connect your phone to your computer and wait a couple of minutes while your computer recognizes it and detects it as a known device. Once you have this, go ahead and run the .BAT file and it will do everything automatically, it will connect to your phone, do its thing and you will end with a rooted phone. Make sure you read the instructions on the .BAT process, like for example “Activating the setting for ‘Unknown Sources’ on your S2”.

Once completed, you can disconnect your phone and look for a new app called “Super User” which is like having a ‘root’ password in a Unix/Linux machine. Any time an app requests for ‘root’ or ‘administrator’ permissions on your phone to do something, you will be able to allow it.

Ok, so far you haven’t voided your warranty (if you have one), and you might stop here as this rooting process may be enough for you, as you only wanted to be able to use root apps. If not, you can continue to the next section: Installing CWM or “Clock Work Recovery Mode”. Attention: this WILL void your warranty.

Installing CWM:

First of all, CWM is just a recovery mode on steroids, which will give you the ability to do backups/restores, install new ROMs among many other things. So, having this at least to back up your entire phone isn’t a crazy idea after all.

To install CWM, you will need to download Odin, which is a software that “pushes” software into your cellphone’s guts. You can find both on this file here.

Once downloaded, again, you need to previously have installed your phone’s drivers. Once you connect your phone and give your PC sometime to recognize it, go ahead and execute Odin. It will take a couple of minutes to recognize your phone, but you will know it did because you will see something like this.

Once you get that, you are ready to “push” the CWM software into your phone. So, go ahead and select the option “PDA” and look for the CWM files (which you can download from here). Try using the latest version available, Google is your friend.

When you finish this process, you now are ready to work with ROMs and backup your current one, however, your phone now is TOTALLY your responsibility, warranty has been affected and any Samsung people will know it because you now have something like this when you boot your phone:

NOTE: there’s a way to get rid of that yellow triangle, you can obtain a USB jig for 10 bucks in Amazon, which will just shut off that yellow triangle for you, and will keep your phone ‘under the radar’. However, I consider this silly, as still if a Samsung technician needs to review the phone they will find it has been hacked and you still are not covered so, this is only if you really hate the yellow triangle to be there. Period.

Backing up your current (stock) ROM:

Ok, this part is HIGHLY recommended before doing anything else: back up your current ROM. This will store EVERYTHING in the same phone, but it will be a way to have a way out if something goes wrong at any point or to just have a backup in case you screw your phone in the future. This backup will reside in your phone’s memory.

First, you need to enter into CWM, to do so: with your phone turned on and the system running press and hold: Volume Up, Center button and Power button at the same time. Wait there for about 5 seconds and your phone will power off and power on again, don’t release any button yet, just hold into it until you see a screen with some wording in orange, blue or green color (depending on the CWM version you find). It will look similar to this:

Once there, go to the section “Backup/Restore” and make sure you use “Backup” option. It will take around 5-7 minutes to do an entire backup of your phone in your phone. Once completed, you can stop if you don’t want to go into anything else and just reboot your phone using the “Reboot phone” option. To go back, you might use a click on the Power button of the phone, although I didn’t test it I heard there is a CWM version that already supports touch feature.

If you ever need to restore your backup, you just need to go to the menu and you will find it if you go to the “Restore” option (duh!).

Installing a new ROM (going for the real thing!):

Ok, this part might work differently on different persons and I really don’t know why. Anyway, you just need to download the ROM and place it on your “downloads” folder inside your phone (a lot of people recommends doing it on the sdcard, but when I tried my CWM didn’t recognize the folder that was on the sdcard, maybe it’s the version but honestly this was the only way I found to do it).

Now, you just have to boot into CWM after placing it in the correct folder and select the option “Wipe data / factory reset”, then you go to “advanced” and select “Wipe Dalvik’s cache” and finally go back to the main menu and select “Install zip from Internal Card” and go to the folder and select the ROM’s zip. This will start the installation process which should take around full 10 minutes. You should do this while you are full of battery to avoid inconveniences. Depending on the ROM you might need to install some other things/packages along with the ROM.

Once completed, boot your phone up and it should take a while so don’t panic, it needs to re-install everything back again but you should be booting up on a new ROM already.

Enjoy!

NOTE: I would like to give special thanks to Max from GalaxyS2Root.com, his work is awesome and everything that is described here + many more things and even ROM reviews can be found at his site. Also, the files I provide in this guide were downloaded from his site, so all the credits (and donations) should go for him. Click here to visit it.