to flash recovery.img. Also there is a simple installation script that I use in terminal emulator:
Download and extract the zip into the root of your sdcard so that the path is /sdcard/rec. Copy desired recovery.img to the rec directory, overwriting the one that is already there. DO NOT RENAME RECOVERY.IMG. Install a terminal emulator from play.and start it. Type "su" (without quotes) and enter. Superuser prompt should appear. select allow. now type "sh /sdcard/rec/rec.sh" (without quotes) and enter. Phone will reboot into your new recovery.