You have been reading this? The part about entering 32 is where they are resizing the internal flash for root (my mistake it wasn't for the /home directory)
Installation:
1. Extract the 3 files - initrd.bin tools.tar updater.sh - to the root of your CF or SD/MMC card.
2. Make sure that Zaurus isn't plugged into AC power.
3. Remove battery for at least 5 seconds.
4. Replace battery (replace battery cover, lock cover), plug in AC power.
5. Press and hold the "OK" button on the keyboard.
6. Turn the power on, you should see the Japanese service menu.
7. Now Plug in the Power Cord. (You will get an error if it isn't plugged in!)
8. Select option 4 (flash/update).
9. You then have several options including CF and SD
10. Choose either CF or SD, depending on which media you put the files on.
11. Select "3 NAND Flash Utils"
12. Select "1 Resize root partition"
13. Enter 32 when prompted for root partition size.
12. Flash will be repartioned and Zaurus will reboot.
13. Repeat steps 2-10 again and wait for the menu start menu.
14. Now select "1 Install new ROM" and wait. Reboot your Zaurus when ROM installaiton is complete.