Update: Fixed download links.
Update2: YES, this tool does require that you have an unlocked Prime!
Update3: Fastboot tutorial updated to use the *BLOB*. This should work fine. Blame Asus/Nvidia for not making fastboot work like it should.
ASUS finally released the unlock! 
This means, it’s time to get CWM on there. Enjoy! We have been preparing CWM for a little while, but for obvious reasons we haven’t been able to test until now Stay tuned for more awesome things for Transformer Prime!
CWM
Download Link: CWM Blob | Just the CWM image | Update.zip(TBD)
Instructions:
- Root your TFP
- Download the blob file (tfp_CWM5_androidroot.blob)
- adb push tfp_CWM5_androidroot.blob /data/local/blobfile
- adb shell & su
- dd if=/data/local/blobfile of=/dev/block/mmcblk0p4
- Reboot!
- That’s it We plan to release an update.zip suitable for flashing from the stock unlocked recovery to make this even easier!
Instructions for non-rooted Primes (or those who’d rather use fastboot):
- Get fastboot from here, and extract it.
- Download the blob file (tfp_CWM5_androidroot.blob), and put it in the same folder as where you extracted fastboot.
- Power off your prime.
- Boot with Volume-down pressed. Wait when you see text appearing. The prime will then allow you to start “fastboot”.
- Open up a command-line prompt, and navigate to where you extracted fastboot with “cd”.
- Enter the following commandline to flash recovery: fastboot -i 0x0b05 flash recovery tfp_CWM5_androidroot.blob
- Profit!