1. Unlock Bootloader using this guide @ http://www.hovatek.com/forum/thread-582.html
2. Download TWRP (PJ75IMG-twrp-2.x.x.zip) @ http://techerrata.com/browse/twrp2/jewel
3. Rename the above file to PJ75IMG.zip and send it to your HTC's SD card
4. Power down the phone, then enter Bootloader (hold the Volume Down button while you turn it back on)
5. The bootloader will automatically scan for any updates and detect your new PJ75IMG.zip file
6. When it asks you if you want to install it, press the Volume Up button to confirm, and you will have the recovery installed
7. Delete the PJ75IMG.zip file
8. Download SuperSu @ http://download.chainfire.eu/315
9. Copy SuperSU-v1.25.zip to your SD card
10. Enter Bootloader again and select Recovery
11. Tap on Install, navigate to the .zip file using the Volume buttons, press the Power button to install, and Swipe to Confirm
12. Reboot the phone
13. When your phone is done restarting, go in your app drawer, open the SuperSU app, and update the binaries. It should ask you to do this with a popup notification, but if it doesn't, you can find it in SETTINGS
14. Done!