[Transformer TF300T Android Development] jgaf:
NEW WAY TO ROOT NO NEED FOR DOWNGRADE NOR UNLOCK

Check out this thread , give thanks to miloj

-----------------------------------------------------------------------------

If you updated to .26 you will need to downgrade to .17 to be able to root your device. If you are on .17 just skip to step #2

STEP ONE

You will need to downgrade using Wolf's 2nd method found here

For this you will need to use ADB, meaning you will need to have Android SDK installed. In order to get ADB working watch this helpful video tutorial (found by tomween1)

There's also a one click script that will do this for you automatically, found here Important note: remember that the automatic script does the same as the 2nd method, so you will need to leave your tablet connected to your pc while doing this. Once you run the script your tablet will reboot in the first couple of seconds (it hasn't finished just yet), then the script will move to the next step, which will take about 10 mins to finish. After this it will reboot and load up the new firmware.

Both processes ask that you have the .17 BLOB file in your Internal SDCard, ASUS had the firmwares previously posted but they took them down. You can Find links to the FWs in the following threads:

US .17 Blob

http://xdaforums.com/showthread.php?t=1642614 (courtesy of wideopn11)

The BLOB file can be found inside the 2nd zip file downloaded from those mirrors.

DE .17 Blob

Should work for downgrading from WW firmwares.

See this post (courtesy of costcutter)

Once downgrade to .17 you can root your device.

STEP TWO

In order to root you will need the apk for SparkyRoot, which you can download here. Just follow the instructions on that thread and you will have a rooted device.

STEP THREE

Do not update your device to .26 just yet! First get Voodoo OTA RootKeeper from the Google Play Store. This application will help you retain root after upgrading. Once you have installed it, open it and follow the instructions inside the app. After making sure that all the check boxes are marked in OTA RootKeeper, you can update to .26

Once you have update you won't have root. So, go into OTA RootKeeper once again and restore your root. Voila!

STEP FOUR

Download and run Titanium Backup from the Google Play Store. It will say that you need to fix some permissions in order to have a fully working root, just tap "Ok" or "Yes" (don't remember which one was it). Then reboot tablet and you are done. Enjoy your rooted tablet!

NOTE:

Remember it is advised that you shouldn't update manually, since you might not be able to restore root. Some people have said that they were able to restore, even while updating manually. Also after rooting, it might take a while to receive the update notification for .26, just keep trying to refresh in Settings>About Tablet>System Firmware Update (be patient, it took me a while to get the update). The firmwares posted in the thread I linked to are for the US, if you have another firmware, non US, for now I don't have links to them. If you do know mirrors hosting non US FWs please post them in a reply message.

This guide hasn't been made from scratch by me, it is a collective work that has expanded through various threads. I would like to thank the following users: wolf849, bpear96, sparkym3, anduzer, wideopn11, demandarin, Gam3r 4 Life, edgemaster191, costcutter, tomween1 and many others that have contributed in finding and hosting this information.

-----------------------------------------------------------------------------

UPDATE .29

It has been confirmed by user Gam3r 4 Life that downgrading from .29 to .26 is possible using the same method stated here. I'm pretty sure that you can go straight from .29 to .17, if you haven't rooted your device yet, with the same method. Someone confirmed a downgrade from .29 to .17 here

-----------------------------------------------------------------------------

UNLOCKED ROOT

There is another way to root your tablet, this only for the people that want to unlock their devices (REMEMBER UNLOCKING YOUR DEVICE VOIDS THE WARRANTY FROM ASUS, YOU WON'T BE ABLE TO GET SUPPORT FROM THEM NOR AUTOMATIC OTA UPDATES....). So, if you want to take this path please look into this thread, in that thread you will find an explanation on how to get CWM running on your unlocked tablet and you will find a flashable file that will root your device. Please read that thread carefully. Also remember to give thanks to XpLoDWilD for preparing it.