Dont have much time today, so here is a very make do post, that I'll update later..
openrecovery-twrp-2.1.2-hwu8815.img MD5: 5e3e2ad5534ddd404f745e22d740d67e
openrecovery-twrp-2.1.2-hwu8815-update_signed.zip MD5: 18f6d17715c23a5e33f0e9fa6f5bc99e
The same method of installation etc as Clocwork Mod, check out that post for more details.
Also, if you have Clockwork Mod Recovery already installed you can use the update.zip to switch it, and visa versa.