This is the newest and preferred way of rooting your Thunderbolt!
Thanks to porsche996 for taking the time to put this together for us.
I took the plunge, and I have to say it was well worth it! Basically, there is now a Root method that eliminates large download files, and pretty much any real problems (at least it worked flawlessly on my phone). Usual disclaimer (you're responsible for your own actions) applies.
This is, LITERALLY, less than a 5 minute process, assuming you have all the files/preliminary stuff done first. Having to do "all" the preliminary should take you another couple minutes, at most... This is THAT simple!
Information you need to have first:
1) Serial number of your cell phone
2) HBOOT version number
3) HTC FastBoot drivers
4) Super User file: su-3.0-efgh-signed.zip
5) Uninstall HTC Sync drivers (or any other auto-sync programs you may have on your computer; you may just need to turn them "off"; I don't know.)
6) Set phone to USB Debugging on, and Always awake
To get into HBOOT, turn your phone off. Then press the volume down button along with the power button. Press and hold, and within 5 seconds it'll come on. This method supports versions 1.04.0000 and 1.05.0000.
Step-by-step Revolutionary rooting instructions:
Step 1) Install HTC FastBoot driver
Step 2) Go to REVOLUTIONARY and follow the instructions to download the file revolutionary-0.4pre3.zip. It will require you to know your cell phone's serial number, and what version of HBOOT you have.
Step 3) Plug your phone in, select "usb storage", and copy the Super User file to the SDCard somewhere (easiest if you don't put it into a folder on your SD card.) Don't unzip it.
Step 4) Plug in your phone, and when the prompt comes up, set to "Charge Only". Disregard any notices and don't install any additional drivers or whatnot.
Step 5) Unzip the Revolutionary zip file into a folder somewhere you can find it.
Step 6) Run the file "revolutionary.exe".
Step 7) Follow the prompts on the screen. It's pretty straightforward. It will reboot to HBOOT a couple times, the last time you'll see it at the top saying "S-Off".
Step 8) It asks you if you want to install clockwork recovery. Select "Y". You'll need this...
You now have a permanent custom recovery on your phone.
Now to actually Root it:
Step 9) From the HBOOT, scroll down to "Bootloader" using the volume keys, and select using the power button. Then scroll/select "Recovery" Yes, it seems sluggish...that's fine. Don't be impatient; it'll let you scroll at some point...
Step 10) Wait! You'll see the HTC spash screen for a bit, and then eventually you'll be into Clockwork Recovery
Step 11) Scroll to "install zip from sdcard" and select.
Step 12) Scroll to "choose zip from sdcard"
Step 13) Find the super user file (su-3.0-efgh-signed.zip) (it'll be at the bottom of the directory list if you put it in the base directory of the sd card) and select it.
Step 14) Sit back and watch the quick show... If all goes well, it will install and show you when it's finished.
Step 15) Reboot the phone (keep selecting "back" until you have the option to reboot the phone)
If you are getting Force Closes from Superuser after you are finished, please reboot into Clockwork Recovery and FIX PERMISSIONS.
YOU'RE NOW ROOTED!!! On a STOCK ROM! No loss of data. No re-setup. Nothing...
I show 15 steps, but honestly, this is about as easy as it gets. I broke things down into very small baby steps so literally anybody can follow it. For the record, my phone had the recovery 1.04.0000 on it, so **maybe** there will be a difference if you have another one, but I doubt it.
Next steps are same as any other root. I always install Rom Manager from the marketplace, as that lets you boot into recovery quickly, and do backups, flash ROMs, etc. from there.
The only "hitch" I had while doing this was when I first started up the phone, it was stuck in 1x data mode. I turned it to "LTE Only", then back to the "CDMA/LTE Auto", and haven't had any issues since. It could have been I didn't wait long enough for the 4G signal to be picked up; I don't know, but I figured I'd mention that just in case.
I HIGHLY recommend reading this page:
As it's Unrevoked's full information on this software. Take in mind, this is BETA software, and I'm not involved in it in any way, shape, or form. I just did this on my phone, and thought I would provide a quick "how-to" to help out others that are curious. I can't answer any technical questions and/or issues with the software, as again, I HAVE NO INVOLVEMENT IN IT'S CREATION!!!
If anybody can take a look at my steps and want to clarify/expand on anything, by all means feel free!
There is now a Youtube video online with a How-To using this method. It is not my video, but it is complete. It has a couple things slightly different (different order of getting license key, and different order for copying the Super User file to the phone). However, it won't make a difference as far as the overall operation goes.
How to Root - HTC Thunderbolt (No Data Wipe! Newest & Fastest) - YouTube
In the event that you need to un-root your Thunderbolt after following these instructions, follow these instructions.
[RS Guide] How Return to Stock from Revolutionary Root