I am not responsible for any damage you do to your device. Following this is your choice.This will void your Asus warranty and you assume all responsibility from here on out.
As long as you follow all directions in this guide your device will not be bricked. It will be unleashed to this beast of a tablets max power
Before you continue make sure you:
1. Have the drivers for your device installed on your computer
2. Have made the upgrade to Jelly Bean
3. Have the USB cable for your Prime
4. Have nerves of steel and the ability to read all and follow instructions in this guide.
Useful Information for total beginners: Some people using this guide may not even entirely understand what they are undertaking. This is not acceptable so it's time for some education. Android is a Linux based operating system (in it's self, not direly important information but it's nice background knowledge) which means that there are certain permissions to users. Having "root" permission is like being an "Administrator" on Windows systems. All devices come without "root" permissions as the total new users can do irreparable damage to their device. This is different than unlocking your boot loader. Unlocking your boot loader (in the Transformer Prime's case) is the act of saying to Asus "I willingly give up my devices warranty in exchange for the ability to totally control my device so I can flash custom software". Unlocking does not automatically give a device root permissions. This can only be obtained through an exploit or by flashing the proper thing after unlocking. Since I'm not perfect at wording (and it's best to educate yourself as much as possible on the subject) there is more info here:
Step 1 Download the Unlock tool here: http://www.asus.com/Eee/Eee_Pad/Eee_...F201/#download (navigate to Downloads, then select the OS as Android, then scroll to utilities and expand the menu. Find the unlock tool and download that. Don't worry about the "For ICS only" disclaimer. This has been confirmed working on Jelly Bean). Install this app on your Prime and run it. Connect to a network before doing so and follow all on-screen directions.
Step 2. By this point the unlock tool has done it's job and when you boot your Prime now has a nice "Your device is unlocked" message in the upper left corner of the screen. The next step is to flash a custom recovery image (TeamWin Recovery Project(TWRP) in this guides case). This may sound complicated but there are multiple easy ways to do this.
Option 1: Go to the TeamWin website and download the needed files as directed on the page and follow the instructions on the website to flash TWRP. (http://teamw.in/project/twrp2/93)
Option 2 (easy option): This option flashes TWRP running a file from your Windows computer. The file attached at the bottom of this guide needs to be downloaded and unzipped to your desktop. Once this is done you power of your Prime and turn it back on while holding the volume down button. Once the tab vibrates release the power button but continue to hold the volume down button.
Once this has been done you will see 4 icons pop up. One is the USB symbol. Navigate to that by pressing the Volume Down button until the icon is highlighted and press volume up to select it (the menu will say use Volume Up to navigate but this is incorrect). This will put your device into fastboot mode. Connect your Prime to your computer via the USB cable and open the folder you extracted earlier. Run the Windows Batch File. This will automatically flash the TeamWin Recovery image for the Jelly Bean bootloader.
Now that you have unlocked and have a custom recovery installed you can begin the flashing. To get into your recovery all you do is power up while holding volume down and select the RCK icon. This boots the recovery image and you'll be able to flash, back up, and restore roms. All threads will have a guide on how to flash the rom in the thread so I won't go into detail. I do suggest however, using a microSDcard to store downloaded roms for flashing as it is safer than internal storage. If you are looking to back up your apps then there's this amazing app called Titanium Backup on the Android Market. It's very powerful and can backup your apps as well as user data.
HELP! Something went wrong and I need help: As with all processes there can be issues that arise. Some are common and others are individual. Let's address some common problems for all you who are still nervous about this:
1. Everything seemed to go fine but my Prime won't boot into TWRP
SOLUTION: This problem comes up for a few reasons and is pretty common. A lot of time it's simply a bad download or you have the wrong files. Check the files you have and make sure they are the right ones. If so then download them again. Sometimes a download just gets corrupted. If neither of these solutions worked either try another method of installing TWRP outlined on their website or post here and either I or another helpful person will do everything possible to help
2. When I tried to flash a custom ROM it won't boot:
SOLUTION: Usually this is an issue specific to the ROM you are flashing. The basic list of problems to eliminate are:
1.Ensure you have a good downloadVocab guide for totally new users:
2.Ensure you have the proper boot loader for the ROM (i.e. JB boot loader for Jelly Bean ROMs
3. Try reflashing the rom. Sometimes something just doesn't work and the only way to fix it is to reflash
Rom(s): Basically the operating system of your device.
TWRP: Team Win Recovery Project. Started by developers here at XDA and is a powerful recovery tool.
Brick/bricked device: Developer term for saying your device will no longer work due to software/roms and is basically a very, very expensive brick/paper weight.
FAQ: Q: My device is on Jelly Bean but the unlock tool will not work for me no matter what I do. What's wrong?
A: Asus has some issues as a company and certain people are completely unable to unlock their device no matter what. I suggest contacting Asus with your devices S/N and politely ask for an explanation and see if the issue can be resolved. Many users who have used the Asus RMA have still been unable to unlock afterwards.
Other useful links: http://www.youtube.com/watch?v=-pW05...2&feature=plcp
Very comprehensive video guide with a full walkthrough to help all with this process. And of course all users can PM me with questions or ask them here.
SuperSU.zip attached is for those who want to root the stock rom. Any custom rom should already be rooted for you.