What exactly do I need to flash to go fully stock on the unlocked variant?

Sorry, I've been on a custom ROM this entire time but I want to flash everything back to stock. I think I'm still on the 1.5xx or 1.3xx baseband, with TWRP. Trying to get to the 1.8xx with stock recovery.

Thanks!

from xda-developers http://ift.tt/2ayLQle
via IFTTT