These are my own notes, so I have a chance of remembering how to do this
First of all BACKUP EVERYTHING!!! I use Titanium Backup Pro (and buy the pro key), and backup everything to an miniSD card, that way the apps and userdata can be restored in the new android rom (even if it’s a diffirent rom).
Grap the latest version of Tubuntu from the thread “[Win32/64][Dual Boot][Mount-Loop] Tubuntu – 1 click installer SBK1 & SBK2! *2/1/2013*” on XDA forums.
Locate the “Prime ROM” on the same page and download it (rename it “system.img”).
Find and download the Linux image you want (on the same page I choose “Lubuntu v1.2 (12.10)”). Rename it “ubuntu.img”.
Download the linux kernel you wan to run, I’ve had success with “2.6.36 – [cpu 1.4 ghz] [gpu 300mhz]“. Rename it “linux.img”. (I don’t get wifi if I use the kernel that comes in the tubuntu package, therefore this is needed for me).
Put all the *.img files in /tubuntu/images/
Backup the tablet!
Remember to select the correct SBK!.
When you’re raedy click “Flash” and sit back and wait. (THIS WILL ERASE EVERYTHING ON THE TABLET!)
When it’s done flashing, let it boot into the Android prime rom and finish the setup (it’s important to go through all the setup and reboot to android a couple of times, even if you’re going to install another rom in a minute).
When that’s done you can boot into Ubuntu (press “vol down” + “power”, then “vol up” when it askes you to), and set up Linux.
The first thing to do is to resize the linux partition (otherwise you’ll run out of space in about 30 seconds). Open a terminal and type:
sudo resize2fs /dev/mmcblk0p8
Now install the kernel supplements, go to the root in a terminal and run:
sudo wget http://novaspirit.com/tubuntu/kernel_sup.tar.gz /
sudo tar zxvf /kernel_sup.tar.gz
Reboot to linux a couple of times and make sure everything is working (it should be!).
Now we’re ready to deploy the Android ROM of choice. I choose the TeamEOS3 Jellybean ROM. Download the ROM and Gapps and put them on a miniSD card.
Connect the tablet to the computer again, fire up Tubuntu (select the correct SBK), put the tablet into APX mode. Go to the Advanced tab in Tubuntu and click to top flash button. This will flash a recovery image that can be used to change the android rom. When it’s done flashing but the tablet into recovery mode (“vol down” + “power”, then when it asks, “vol up”). Do a “Factory reset”, then install the TeamEOS3 ROM. Restart the tablet and run through the setup process in Android. Restart to Android a couple of times more to make sure everything is working, then go back to the recovery mode and install the Gapps. Start android once again and make sure everything is working correctly (including Gmail, Maps and so on, you may have to find them in the store though).
The final step is to connect the tablet to the computer in APX mode one last time and click “Flash” again in the Advanced tab in Tubuntu (if you’ve had it closed in between flashing the recovery image, the button will say “Reflash”). When it’s done you should have a tablet with both Android Jellybean and Ubuntu! )