Forgive me, I'm a bit of a newb, but how exactly do you get the textures from the Warden Commander's Armour and Blood Dragon armour out of the module and into a plain .dds file for editing?

I've seen plenty of BD retextures, and want to retexture my own as well, along with the WK armour sets.
I already know how to reskin an item, I've done it to several things so far. The DLC .erf files are encrypted though, so is there some kind of trick to getting the textures out?
Thanks in advance!