1. The first thing for you to do is to switch on the device.
2. Press and hold the Power & Volume Down buttons for five seconds or so.
3. Let go of the Power button when an HTC logo shows on screen.
4. Now use Volume buttons to select the Bootloader option. Press Power button to confirm.
5. Select, in the same fashion as above, Reboot to Recovery Mode.
6. Good job, you are in Recovery mode. Navigate it with Volume buttons; select options with Power button.