HOW TO: downgrade, root and upgrade ANY G1/Dream (even Continental European)

"Requirements:
- Micro SD card formated FAT32 (128 MB to 2 GB), Sandisc cards may not work (but worked for me).
and
- Connected Windows Mobile device (application unlocked)


SD Card:
- Format recommended
Code:

format F: /FS:FAT32 /A:4096

(Replace F: with your SD card reader drive letter.)


TESTED, WORKING
1. Insret SD card to WM device and connect it do desktop. WM has to be application unlocked.
2. Download QMAT (http://revskills.de/pages/download.html)
3. Start QMAT and select Hardware Forensics -> Generate HTC Goldcard
4. Select Dream from the list of devices, Click "Get SD Card Serial from WINCE Device" and then "Save Goldcard Image to WINCE SD".
5. Copy DREAIMG.NBH to the root of sd (UK - RC7 recommended for our DREA110)
6. Power off the G1, put the card inside, hold camera button and press power button
7. Press power button to start flashing
8. To apply HardSPL, root & upgrade: http://forum.xda-developers.com/showthread.php?t=442480
9. You don't need the GoldCard any more (HardSPL fixes it, you should be able to flash any image now). So format the SD once again or borrow to a friend to downgrade his G1. " forum.xda-developers.com