twrp-shooter-2.0.0RC0.1.img
Download the above file. Turn off your device. Turn on the device and keep holding volume down until a menu shows up. Select fasboot from the menu list. Plug the device into your computer. If you have the right drivers installed, your screen should now say FASTBOOT USB. Run the following command via the command line:
fastboot flash recovery recoveryfilename.img
Note that you will need to change the last part to match the name of the file that you just downloaded. This method requires that you have the drivers installed that come with the HTC Sync software that are available
here. You will also need adb and fastboot for your computer.
OR
PG86IMG-twrp-shooter-2.0.0RC0.1.zip
Download the above file. Using a file manager such as Astro or ES Explorer (both free in the market), rename the file to PG86IMG.zip (capitalization matters!) Turn off your device. Turn on your device and hold volume down the entire time that it is booting. Once the screen comes up, it will scan the sdcard for the PG86IMG.zip. Tell it to install. Once it is done, tell it to power off. Power on your device and let it boot android normally. Use your file manager to delete or rename the zip file. You can now reboot to recovery and use your bootloader normally.