This is also a great guide to help fix any stability problems your phone is having in general.
If you just need to unroot to send the phone back to Verizon or to sell it to someone, stop after step 17 and reading everything after it, but before step 18.
If you do not follow these directions perfectly, you have a chance of damaging your phone. Part of this process involves flashing hboot manually through ADB, which is dangerous. PLEASE PAY SPECIFIC ATTENTION TO THAT SECTION OF THIS GUIDE. If you don't, your phone is going to be a very depressing paperweight.
IF AT ANY TIME YOUR PHONE TRIES TO ACCEPT AN OTA YOU NEED TO DENY IT! Because of how the Revolutionary Team's S-Off Tool works, we need to be in Froyo to flash hboot manually. An OTA will only get in the way!
Make sure your phone has a decent amount of battery (More than 50%) and keep it plugged in whenever you boot to hboot to be safe. If your phone powers off or dies when flashing a PG32IMG.zip, BAD BAD BAD things will happen!
I am also not responsible for anything that happens to your phone. If you're rooted and S-Off, you already know the dangers, so be smart!
Before I get started though, I have some people to credit, as their tools are used in this guide.
notluK for his Unroot Guide on Android Central. Pretty much all of this guide is a direct kang/plagiarization from him, with minor changes due to file hosting fiascos.
CLSShortFuse for his SuperOneClick tool
The Revolutionary Team for their S-Off Tool
The unrEVOked Team for hosting the HTC Fastboot drivers
I think that's it... now, for your bacon.
NOTE: I do not have the original md5 sums for these files, so don't ask. Just download over a reliable connection (NOT ON YOUR PHONE!).
HTC Fastboot Drivers
Froyo (2.2.1) PG32IMG.zip
Gingerbread (2.3.3) PG32IMG.zip
Super SU ZIP from here
And a significant amount of time and patience
Okay... here goes. Please make sure to keep all of the above files on your PC to be safe. They are always good to have in case your phone goes screwy.
1. Download and install the Android SDK, install the HTC drivers and then reboot your PC. (If your SDK is fully functional and you already have the Fastboot drivers installed, just skip this step.)
2. Put the Froyo RUU zip on the root of your SD card and rename it to PG32IMG.zip (if Windows is hiding your file extensions, don't add the .zip to the end).
3. Boot your phone into the Bootloader (Vol Down + Power while off)
4. Press Vol Up to accept the update
5. Reboot phone when done (It may power off to a black screen instead of actually rebooting. Don't panic, just turn the phone on like you normally would ) When it's done booting, delete the PG32IMG.zip from the SD.
6. Check your OS version under Menu>Settings>About Phone>Software Information. Verify your OS version as 2.2.1.
7. Enable USB Debugging under Menu>Settings>Applications>Development
8. Plug in your phone and run the SuperOneClick root tool. When it asks if you want Busybox installed, say Yes. This is important, as you will need Busybox to verify the md5 of the hboot image you are about to flash to your phone manually.
9. Reboot your phone
10. Find the Froyo PG32IMG.zip on your computer and find the hboot_0.97.0000_336906.nb0 file inside. Extract it and put it in the platform-tools folder of your SDK.
11. Make sure your phone is still plugged in and then open your Command Prompt/Terminal and cd to your SDK's platform-tools folder, and follow the adb commands below, with your phone still plugged in, of course!
EXAMPLE: This is where mine is, yours may be different, so check!
adb devices (make sure ADB sees your phone if not, this is an appropriate time to ask for help :)) adb root adb remount adb push hboot_0.97.0000_336906.nb0 /data/local/
12. Now, do:
adb shell su /system/xbin/busybox md5sum /data/local/hboot_0.97.0000_336906.nb0
If you skip this step, you're a big, dumb idiot. This next step involves flashing something to what is probably the most important partition on your phone. If you mess this up, no one can help you, and your phone is permanent brick.
13. If the md5sums match, continue:
adb shell dd if=/data/local/hboot_0.97.0000_336906.nb0 of=/dev/block/mmcblk0p18
adb shell /system/xbin/busybox md5sum /dev/block/mmcblk0p18
16. Press Vol Up to accept the update.
17. Reboot into GB when done.
If you accept the 2.3.4 OTA before going S-Off, you will have no way of reverting and back and re-rooting, SO DON'T DO IT!
The above may not be true, but I'm pretty sure it is, so PLEASE, for your own good, DON'T ACCEPT THE OTA!
If you needed to unroot to send the phone back to Verizon/wherever you got it from, or to sell it, this is the place to stop. If you're selling the phone to someone and they know what rooting is, they'll thank you for not updating to 2.3.4.
18. Run Revolutionary like you did before and accept the installation of ClockworkMod recovery (It'll be an old version, but that's okay).
19. Put the SuperUser zip from earlier on your SD and flash it like normal. (Backup first if you want to have a backup of factory stock unrooted)
At this point, your phone is now at root 2.3.3 stock and S-Off again! Update your ClockworkMod recovery (or use 4ext, which I like a lot), make a backup (PLEASE, MAKE A BACKUP!) and then flash the rom of your choice, probably an ICS one.
Feel free to update your radio and stuff too. Things should be working much better than before.
And, to be safe, never OC past 1.3ghz. You shouldn't ever need to anyway, and it can break things, which means you'll have to do this all over again. Overclocking too high and my phone overheating is how I got into this situation in the first place, so I'm not just blowing hot air here. (Haha, get it? :P)
If anybody has any questions (please, don't bombard me with them ), feel free to post here and I'll do my best to respond in a helpful and timely manner.
If this helped you, click the "Thanks" button, or I'ma find you!