If you are making a new one from scratch instead, make sure you check Is CharGen Face Preset. You can open up one of the existing presets (they all have CG at the start of their ID) and save it with a new ID and it should be set up correctly. The character gen preset shouldn't have any factions or inventory or anything else. So go to the source NPC, press Copy, go to the target NPC, press Paste, then change the selection from Brow Ridge High/Low (or whatever is currently selected) to something else and press Paste again. The second thing is that when you do copy and paste from the Face Advanced tab, whatever option is selected (by default it's the first one, Brow Ridge High/Low) will not be copied. First, you need to copy the hair color over to the target NPC first (the three RGB values under the Face tab), otherwise when you change the hair color the facegen data will change slightly. There are two bugs you need to be aware of.
There is a copy and paste option under the Face Advanced tab. Once you have the face in the GECK, you can copy the face from one NPC to another by opening both NPCs in the GECK.
There is a link in the description to a detailed tutorial by Jokerine.
