I used this method to root my Tunderbolt yester to start the debloat process. As it turns out, I didn't need to root. Instead, I suggest using the psneuter method to freeze bloat applications found here:
Temp Root just to remove bloat apps? - xda-developers
One piece of advise, I followed the directions there, but no where in the steps dis it included getting getting psneuter for the process to actually work. You will need to find and download psneuter in addition to those steps listed. That method worked on my wife's non-rooted TB.
Back to using this method to root. The process was fairly lengthy from downloading 800MB from a throttled fileserver to actuall pushing images that large to the phone. From start to finish it took about 4 hours, but 2 of those hours were just downloading the file.
Before step 1: I had already installed the JDK (Java Development Kit), Android SDK, and HTC Sync drivers while trying to use the psneuter method above, so some if not all of these steps will also need to be done if attempting this process.
Step 1: Worked perfectly without any problems.
Step 2: Generated an error and I had to kill the rooter process and start step 2 over. The second time I ran step 2 it completed without any errors.
Step 3: The process completed without any errors and the phone did not reboot. I thought I had root, but the phone wasn't actually rooted. A while later I re-ran just step 3 and this time the phone rebooted at the end of the process and I had root access.
I'm not actually going to use any of my new found root power (except backing up my settings with Titanium Backup). My initial goal was to de-bloat the phone and the psneuter method for that was much easier so I recommend that instead if all you want to do is debloat.
Good luck.