[G1 Q&A, Help & Troubleshooting] TheShortybro:
Warning: Please do this at your own risk. This is not the safest method for doing this. It is much safer to flash this with fastboot. Although there are lots of good reactions in doing thid. I am not responsible for damage or even bricking your phone - Do not skip anything here, please follow everything on this post.

Today I am going to teach you how to

flash

the 1.33.0013d/2.22.28.25 combo in Amon RA recovery! Like I said, this is not the recommended method, but it works, when you follow EVERYTHING on this post.

WARNING:

1) flashing a 2.22 radio via recovery if you have a 3.22 or 1.33 radio via recovery *will* brick your phone

2) flashing the 1.33.0013d spl with a 1.22 radio via recovery *will* brick your phone

So, first off, you have to be rooted.

When you are rooted, you have to have Amon_RA recovery installed. On how to do this, I have a tutorial for it here:http://xdaforums.com/showthread.php?t=1623954

Now, you have to upgrade your phone to Danger/Engineering SPL. It's called like that, because it has a danger of bricking your phone, and it enables fastboot - a tool, that gives you the oppertunity to flash ROM's and such from your computer.

It's like a recovery, but from your computer. To do this, click here:http://wiki.cyanogenmod.com/wiki/HTC_Dream:_DangerSPL

After you do THAT, you can finally start to flash the 1.33.0013d SPL and 2.22.28.25 Radio. This will produce 14 mb of extra RAM for you, but won't be able to play 3D games, like Temple Run. But the 14 mb of RAM really makes a difference. Also you won't be able to use CyanogenMod ROM's, although you can temporarily switch back to Danger SPL. Just look in the EzTerry thread.

You can find the links for those down below:

HBOOT: http://code.google.com/p/g1tools/downloads/detail?name=HBoot-1.33.0013d.zip&can=2&q=

Radio:

http://rapidshare.com/files/43135125...22.28.25_S.zip

Now, put all file to your SD-Card, and reboot into recovery. *TIP* If things go bad, please make a Nandroid/BART backup before you do anything. And one thing, make sure that your phone battery is full, as in green LED, before you flash any Radio/HBOOT, or simply plug your phone into your charger. Now, go to the wipe section in your recovery, and just wipe everything, like press every option you have and wipe. Or simply use Oshaka SuperWipe. Oshaka SuperWipe is reccomended, because it wipes some things, that your recover does not.

After your wipe, go to install zip form SD-Card, then pick your Radio file (update-2.22.28.25 blah.zip and install it. If it reboots or goes to a unpack a MyTouch 3g screen for 3 minutes or so. WHILE YOU'RE DOING THIS;DO NOT IN ANY WAY INTERRUPT THIS; THIS WILL BRICK YOUR PHONE; IF IT STAYS FOR 10 OR SO MINUTES; YOU MAY DID SOMETHING WRONG AND YOU BRICKED YOUR PHONE :( , SO DON'T BE IMPATIENT BY PULLING YOUR BATTERY! After that it reboots and goes back to recovery. Then go to Flash zip from SD-Card and choose the HBOOT-1.33.0013d.zip file. It will install itself and remember, dont be scared by long waiting times. Now, if you did what I said, power off your device and press [POWER+CAMERA] . It says:

DREAM PVT 32B SHIP S-ON

HBOOT-1.33.0013d

CLPD-4

RADIO-2.22.28.25​

Congrats! You just installed a new Radio/SPL combo!

If I helped you, please push that 'Thanks' button!