In the meantime it's possible to use the character creator to change your follower or NPC appearances. It's the best solution, until we get esp mods for appearances.
You need 2 NPCs, the one you want to edit and another noname NPC that you won't see again.
Use a console command to store your own character's look on the noname NPC, temporarily. Then use a console command to put your follower's appearance on your own character. Edit this in the character creator. When finished, put this new edited look on your follower. Finally, take your original character's look from the noname NPC and reapply it to your own character.
Console commands (~):
1. capp player // applies your own character appearance to the NPC selected
2. player.capp [id] // applies NPC/follower id look to your own character, the NPC who's look you want to change
3. slm player 2 // enters the 2nd stage of character creation editor
4. capp player // applies your character's new look to the NPC selected, the NPC or follower whose look you want to change
5. player.capp [id] // applies NPC id look to your own character, this should be on the noname NPC who has your original look
https://www.reddit.com/r/Starfield/comments/1678lgb/showlooksmenu_for_npcs/
And follower Sam's hat can be removed:
https://www.reddit.com/r/Starfield/comments/16fcbvi/comment/k0ernml/?context=3
Also need to add a txt file and command to StarfieldCustom.ini to refresh the NPC and keep the game from resetting the skin to the NPC default on each game load:
https://www.reddit.com/r/Starfield/comments/169mxp6/comment/k0bb7nc/?utm_source=share&utm_medium=web2x&context=3
Sam modified:
Barrett modified: