Thanks Scrupul0uss for this excellent UDE2 guide... it was a huge help for me and many others Im sure. I would like to share my experience after having now soft modded 4 boxes based on your tutorial. Hopefully this will help someone.
Since I was actually adding new HDs at the same time I was doing the soft-mod, I found it easier to arrange the hack, prepare the new HD (create the drive partitions and format them) using
xboxhdm and add the new dashboards all on my PC. Then I just cold swap the HDs, thus preserving the virgin state of the stock HD.
In my variation of your technique I combined some steps, did some in a different order and was able to omit some others too
I start with unpacking xboxhdm to my PC and I do all my file manipulation in the unpacked file structure prior to moving the files to the HD. This is a good time to read the How To text files on xboxhdm and get familiar. Its a short read.
Then I use the Mech Assault hack, which was easy with an Action Replay card (starting with step #7 from your tutorial) to gain FTP access to the xbox.
I FTP the C and E drives from the xbox (step #14) to the C and E folders under the linux folder of the unpacked xboxhdm and move the eeprom.bin file to the eeprom directory in the linux folder.
In the C folder I rename xboxdash.xbe to org-xboxdash.xbe and hex edit it here (step #68). Then patch the original update.xbe from xodash with the UpdateXBE util, saving the patched xboxdash.xbe file to the C folder (step #24).
I rename the fonts folder, add the new fonts folder and the required font files as you describe as well as move the PBL_MeeToo files to the E folder (Steps #41-46).
I extract the Evox files as you describe (step #67), but to the C folder, and edit the .ini at this point so that MSDashBoard = org_xboxdash.xbe.
Next in the E folder I create an Apps folder and an avalaunch folder under that and unpack the avalaunch binary there.
Now I follow the xboxhdm instructions to create my .iso file and burn my boot CD which contains all the utils needed to set up the new drive and all the files I want on it.
I power down the PC, take out all my HDs and place the new HD to be formatted for the xbox on the primary cable by itself.
I then boot from the CD and choose the first menu option: 1) Boot VGA console with xbox-drive utilities (default)
At the next menu, I select option: 1) Build a new Xbox HD from scratch which will lead you through the creation of your new partitions and formatting them as well as copying the backed up C and E folders as well as the new F folder to the new coresponding drive partitions. This will include all previous save games from the stock HD, the new soft-mod and dashboards (evox and avalaunch).
Now I reboot from the CD to get back to the first menu and and choose option: 3) Boot linux with locking/unlocking utilities
I give the lockhd a command which grabs the info from my eeprom.bin and automatically generates the new password to lock the new HD. I write it down just in case and confirm the action.
Thats it! Now just swap your old xbox HD for your new one and put your PC back together if all went well. Worked smoothly for me four out of four times
your mileage may vary!