Well, you already knew that HTCDev.com has been unlocking the HTC-made Android handsets since August and HTC Sensation was the first compatible handset with HTC’s online bootloader unlock tool. Yesterday, HTC has added this support for all HTC devices released after September 2011, including HTC Rezound, and Vivid. A couple of another HTC devices has joined the party today, including the first 4G LTE capable HTC-made Android phone. Both the Verizon branded HTC Thunderbolt and HTC Droid Incredible 2 handsets now can be unlockable using HTCDev’s bootloader unlock tool.
You can check out a detailed guide on how to unlock the bootloader on HTC Thunderbolt and Droid Incredible 2 handsets. So, if it’s the bootloader unlock you’re after, hop on over to HTC’s bootloader unlock page (hit the link) to get into the unlocking process,
The bootloader unlocking process seems to be simple and intuitive, but keep in mind that using this legit method could lead to voiding your warranty. So proceed at your own risk if you are comfortable with this issue.
Source: HTCDev Center