**Edit: If you have unlocked your phone using the HTC unlock tool you will need to relock the bootloader. This process WILL NOT WORK with an unlocked bootloader**
**Edit #2 (5-20-12): Here is a link to another XDA post describing how to root if you have received a warranty replacement. I imagine this will also work with if you are just now trying to root for the first time. http://forum.xda-developers.com/show....php?t=1650519 **
This is all based off of the post on XDA forum from attn1. All credit goes to attn1 and the persons listed in his original post.
All comments I have seen on this method have stated that it is not for noobs and shouldn't be attempted. I will say this, once I figured out what I was doing wrong, the process was very simple and automatic. I will explain what I did right and wrong in an attempt to help anyone looking to root their Droid Incredible 2 with 2.3.4.
Here is the link to the post over on XDA forums:
Read through it and download everything it tells you to. I would suggest saving all downloads to your desktop for now so you know exactly where they are. Once you have done that you will need to move the vwhk-12102011-c.zip file to the root (not in another folder) of your C: drive. The easiest way to do this (for windows 7 users) is to click on the file folder in the bottom left corner of your screen, then click on the OS (C: ). Drag and drop the file from the desktop to the C: drive. Once it is there right click on the file and select extract all. You are now done with the C: drive and can close that window.
Connect your phone to the computer via the data cable. Close the auto run window, and do not let the phone install the Verizon software. Makesure you have USB debugging turned on (menu>settings>applications>development>USBdebuggi ng) and that the phone is in charge only mode.
Next click on the start button and in the search field typein CMD. This will bring a pop up list with CMD (command prompt) at the top. Right click on CMD and then click on run as administrator. You will get a warning window pop up asking if you want to do this, click on yes.
You will get a command prompt that looks like this:
Type in cd c:\vwhk-12102011-c then hit enter. Don't forget the space between cd and c: (I did and it took me a while to figure out what was going wrong). You should see this:
Now type in hack-vivow then hit enter and let the computer and phone do its thing. The safest thing to say at this point is to not touch the computer or the phone. Your phone will restart a couple of times during this process and I can't emphasize enough to not disconnect anything during this process.
When the downgrade completes, proceed to the revolutionary website to root your phone. Before attemptingto root via the revolutionary method remove the battery and write down the serial number of your phone. You will need it for the rooting process. If you have any questions please post them here.
Credits: copied from attn1’s post on XDA
Attn1 – recognized developer over on the XDA Forums forputting this process out there for us
Revolutionary - for everything they do
Ch4lky - zergRush
Scotty2 - misc_version