TRANSFORMER, LINUX IN DISGUISE
ASUS Transform TF101 running Android 4.0.3
USB tether cable for Transformer
MiniSD card (or adapter for a microSD+microSD card)
Plug the cable from your Transformer to the host PC. I kept this cable connected throughout the entire process.
ROOTING FOR THE GOOD GUYS
To install Ubuntu, I first needed root access to the Android system. By following the instructions here
http://hdfpga.blogspot.com/2012/03/one-click-root-for-asus-transformer.html , I was able to root my device. I had to download the flash kit from here http://www.bergfiles.com/i/bf4baf218ch32i0 instead of the link provided in the instructions. Basically just select option 1 and the program will take care of itself.
TANGO DOWN, RECOVERY IN PROCESS
Next I needed to install a program called ClockworkMod Recovery. Using the instructions here http://www.androidauthority.com/eee-pad-transformer-clockworkmod-recovery-installer-61334/ I installed CWM by downloading the RecoveryInstaller.apk file, copying it to directory where I unzipped the primetime rootkit from the previous step, then doing ./adb install RecoveryInstaller.apk
Make sure to have an SDCARD that is partitioned as ext2 - I had some trouble originally with a FAT32 formatted card.
Create the kernelblob using the instructions from the first post here
Now copy both the kernelblob and ubuntu.img onto your SDCARD, insert the SDCARD into your Transformer, and boot the Transformer into CWM recovery mode.
REMINDER - From the Android Authority link above -
To manually boot into ClockworkMod Recovery, power off your Asus Eee Pad
Transformer. Press and hold both Volume Down and Power buttons. When
you see words scrolling at the top left of the tablet, immediately push
Volume Up within 5 seconds.
Once the transformer is in recovery mode, get an adb shell up by doing
./adb shell from the PC.
This shell should have a # sign - which indicates you have root privileges. Run the following commands from the prompt.
mount /dev/block/sda1 /sdcard
dd if=kernelblob of=/dev/block/mmcblk0p4
dd if=ubuntu.img of=/dev/block/mmcblk0p7
The last dd command will take some time, but once it is done, you can select Reboot System from the CWM prompt on your Transformer. The first time you boot, it may take a long time (something about on-line partition shuffling?) but eventually you will see a standard Ubuntu first run setup prompt.
Currently the only issues I have found are - no sound and no flash. There are fixes for these on the xda-developer forums but I have not had time to do them yet.
WALKING THE WIRE... BACKWARDS
There may come a time when you wish to go "back to stock". Fear not! Simply follow the link below.
Note: I had to format my micro SDCARD to FAT32 for this to work... very strange since I had the opposite problem before.