I know I am replying to a forum that's really old, but in case anyone still checks for an answer to this issue - I found a way to change per-loaded npc's clothing without having to reload to an earlier save or start a new game. The solution is really simple actually and involves just using console commands to temporarily have the npc join your party (instructions on how to do that are here at 'runscript zz_addparty NPCname' or 'runscript zz_test_hire' whichever one works for you best) and then equipping the npc with new clothing in their inventory. Again, I may be just posting something that no one sees but hopefully this might help someone out there who like me, didn't want to play with a naked Arl Eamon their entire game!
