The RC33 update is now available to public. If you’re not computer illiterate, I would wait until this update is available directly to your phone tomorrow. But if you can’t wait, read below.
Note: You must currently be on RC30 for this to work.
Mandatory warning: Updating firmware can be a delicate procedure, so continue at your own risk. Always back up everything. Make sure to check the hash or otherwise verify a firmware’s source. Whenever possible, download it directly from Google (as you will in this tutorial). Make sure that your battery is charged so as to keep it from fizzling out mid-update, and that you don’t have the G1 plugged into USB during the actual update process.
1. Grab the RC33 update from Google here.
2. Rename it from signed-PLAT-RC33-from-RC30.f06aa9b3.zip to update.zip, and place it at the root (the very top directory) of your Micro SD card. (If you added the file to your microSD card by connecting the handset to your computer via USB [rather than using a dedicated microSD card reader], make sure to unmount it and disconnect the USB cable now.
Source – mobilecrunch.com
3. Turn off your G1, then turn it back on by holding the Home+End keys until you see an icon popup after the T-Mobile G1 logo.
4. From the icon screen, open the keyboard and hit Alt+L. This allows you to see what’s going on during the update.
5. Press Alt+S to begin the update. Remember, the update needs to be in the root of the Micro SD card and needs to be named update.zip.
6. Once it finishes, follow the onscreen instructions and press Home+Back to finish.
7. The G1 will reboot a few times to flash different parts of the firmware.
If all went well, you should now be running the latest update, RC33. To make sure all your hard work wasn’t for nothing, hit Menu > Settings > About Phone > scroll to Build Number. You should see RC33 in there somewhere. Congrats!
Notes:
- Some microSD cards don’t seem to play friendly with this process. If you have trouble with one card, try another..
RC33 download link obtained via the always ingenious xda-dev community.

