That's literally it for the new body NPC Appearance Changer.

Once you have the meshes for the body and hands, just drag them to your NPC mod and overwrite. You change where the output files go with the Settings tab in Bodyslide. Back on LE i used to have Familiar Faces that allowed me to create a pseudo follower with the looks i wanted but on LE i cant even edit the NPC faces All you do is go into Bodyslide, create the body/hands/feet BUT send the files to a desktop folder.

Apply a racemenu face preset to a follower/NPC - posted in Skyrim Special Edition Mod Talk: Is there an easy way to apply a racemenu preset to a follower or NPC? Ive seen some tutorial of how to create a standalone follower but they all seen too complicated and outdated (they were for LE).