Here is quick UDE tutorial for those needing it:
1. Get the required files. You need the fonts you're gonna use, the update.xbe you're gonna use, xbedump.exe, and the version of PBL you are gonna use
2. Use the gamesave exploit on your Xbox. Lots of tutorials on how to do this out there. Do it however you like - just get that gamesave onto your HDD. Then run the "Run Linux" option in the game and the dashboard will run. Set up FTP access etc.
3. IMPORTANT - Backup your entire HDD, and your EEPROM. This is so you can fix it if you mess up. You don't wanna turn your Xbox into a doorstop now, do you?
4. Uncompress your copy of PBL. Make sure the .xbe is called default.xbe. Extract XBEDump in the same dir. Go into command prompt and go into the correct directory. Type:
XBEDUMP default.xbe -habibi
5. Edit your pbl.ini making sure it has the correct RC4 key. If not, obtain the key from elsewhere and copy and paste it in.
6. Copy your BFM bios of choice into the PBL directory. Rename it to xboxrom.bin
7. FTP to your Xbox. Delete c:\xboxdash.xbe and upload update.xbe. Rename update.xbe to xboxdash.xbe.
8. Go into the font directory and delete the fonts that are there. Upload the fonts you are using - do not rename them.
9. FTP your copy of PBL to your e:\ making sure that the filename for PBL is default.xbe.
10. Upload your dashboard of choice to wherever the bios is set to run it from. e:\evoxdash.xbe is a safe bet
Voila. One UDEd 'box.