How to un-install HTC's gingerbread ROM for Desire

Question

I installed HTC's official (developer-only) Gingerbread ROM on my HTC Desire, but I'm not too happy with it, since it keeps running out of internal memory. So I've been searching for a way to revert back to the original FroYo firmware, but I couldn't find it.

Also, I tried to root my phone so I could install CyanogenMod, but that didn't work: apparently, my firmware is too new.

So, what's the best way to revert back to official FroYo? Or, failing that, to root my phone?

UPDATE with some context: I never rooted, or tried to root, my phone before this failed attempt, and I only did it because I couldn't find an official means to go back to FroYo. I tried both Revolutionary.io and Unrevoked. The latter complained that my firmware is too new; the former just got stuck while "waiting for fastboot".

UPDATE 2 I just tried to install a RUU, but it complains about the boot loader being too new. So no help there, either.

Answer 1

The best known option for the HTC Desire is to use unrEVOked - http://unrevoked.com/recovery

unrEVOked has the added benefit of flashing in a version of Clockwork Recovery. That way you can just boot into recovery, do data wipes, and flash Cyanogenmod.

Note that there is a chance that Gingerbread could prevent unrEVOked from performing its usual processes. In addition, your previous rooting adventures could have placed an alternate recovery into the phone as well. I believe you can press Power+Vol-Up when starting the phone to invoke recovery mode. If Clockwork is present, you may proceed to flash away.

Answer 2

I was able to root my phone using Revolutionary.io after all, following the steps described here. However, instead of running ./revolutionary as described on the page, I had to use sudo ./revolutionary to make things work.