Install/update ClockworkMod Recovery for S-OFF users:
1)Reboot into bootloader by holding Volume down while powering on.
Connect to computer via usb. You'll see "fastboot usb"
2)Open adb on your Computer and type:
fastboot devices
if you see your device, fine. if not, don't start to worry! Sometimes your device does not show up, but fastboot works anyway.
3)Next step is flashing the recovery. Download recovery.img and type in adb:
fastboot flash recovery path-to-your-recovery (e.g. C:\recovery.img on windows)
4)Wait for flashing process to end.
5)When done, reboot your device and boot into recovery to check if it worked.