If you've poked around the editor enough. However, there was a NPC face replacement project by Motoki which incorporated all that for you-- saving you work of having to learn how to do things yourself.
All it involves is reassigning the default body parts skin files from normal NPC to the ones you want (Rhedd's heads presumably) in a pre-made or new mod.
Howeever as for the download... Last I checked, I couldn't find that download. I wanted to download Children of the Night 2, but it was too big at the time to do it in a reasonable time. Now... I can't find it again Bah.
*sniff. I had to reformat my MW Hard drive too, now all my old mods are gone.