Credit: con247 for this very simple, yet informative guide. Thank you!Recovery Installation Method: The PH98IMG.zip
CWMPH98IMG.zip (ClockWorkMod Recovery)
AmonRaPH98IMG.zip (AmonRA Recovery)
This method uses a file called PH98IMG.zip to install the custom recovery. This is the simplest and doesn't require knowledge of fastboot, adb, and doesn't need a computer.
1) Download the PH98IMG.zip of the recovery of your choice. I have them named with the type of recovery in front of it so you know which one to download. For example, CWMPH98IMG.zip is the PH98IMG.zip of CWM recovery. Just rename it to PH98IMG.zip
2) Connect your phone to your PC (if you downloaded the PH98IMG.zip directly from your phone's browser, use a file manager to duplicate these steps)
3) Enable USB Mass Storage (as if you wanted to copy a file to the memory card).
4) Copy the PH98IMG.zip to the root (not in any folders) of the external SD card. NOT the HTC Storage. This is extremely important. It should not be in ANY folders.
5) Disconnect the phone from the computer and shut the phone down.
6) Pull your phone's battery. It should not have the USB cable in it either.
7) Put the battery back in. Press and hold the volume down button and then press the power button. You should get taken to a white screen. This is HBOOT.
8) Some green text should scroll on the screen. At the bottom, it will prompt you if you would like to install the update. Press the button associated with YES. It is most likely volume up, but I cannot remember off the top of my head for sure.
9)When it finishes, it will ask you to press power to reboot. Do this. If you have no signal after booting, it is most likely because you forgot to put the battery door back on, as the antennas are in the door.
10) Delete the PH98IMG.zip from your memory card, or else you will not be able to get into recovery.
11) Custom recovery is installed.
**Temporary Notes: (These most likely won't apply in the coming weeks)**
CWM has issues right now with backups. For this reason, I would recommend AmonRa for now. Also, CWM is not "official" yet, so it will NOT show up in ROM Manager.
Finally, if ROM Manager begins to show CWM for this device, it will not flash via ROM Manager because our S-ON/Unlocked situation.
How to access custom recovery.
1) Power down your phone and pull the battery. It should not be connected to a computer.
2) Press and hold volume down and power to get to HBOOT.
3) Use the volume buttons to scroll to recovery, then press the power button.
4) The HTC screen will flash briefly and you will be taken to recovery. You navigate with the power button and the volume buttons.
How to root (Permanently).
This rooting method again doesn't explicitly require a PC and is permanent until you actively remove it.
1) Flash AmonRa Recovery. Use the other section to do this. If you already installed CWM, this will overwrite it and there won't be negative effects.
2) Boot into AmonRa Recovery.
3) Scroll to and enter the Developer menu.
4) Scroll to install Su. DO NOT INSTALL THE ENG (Unguarded) one. Use the other one.
5) Confirm this, when it is finished, go ahead and reboot. You should be rooted.
6) You can now reflash CWM if you want.
The original author of this suggests doing a Nandroid backup of your device after this is complete. Can be done via either recovery that you choose.