INSTALL GENERAL:
0) Loading UFO last/lowest in load order is first step.
1) Don't have a follower following you in a save you will first install UFO with. If you do it will mess things up as in dismiss original follower on first hire, give you one less spot for follower and maybe more trouble later on.
2) Recommend you do it on a clean save - mostly from other more follower mods (don't forget to dismiss followers before uninstalling such mods, cause they might play naughty with your save game)
3)If you, when first install UFO, are standing by your potential follower they will take up to 3 seconds to get gear, so be ready for it. It's a big starter script so takes time.
4)Each follower will get a default gear to inventory, this is to replace outfits.
5) If you where using TCG disable it before installing and make a clean save from it too.


UNINSTALL:
1) MAJOR THING: Before removing you need to go to Riverwood. On the river island there talk to Tina the Firefly. Yes she's a firefly. Only when you get dialog saying "It is done, please quit game and remove UFO files." can you make a save and uninstall.
--WHY?-- If you don't, all follower will have Outfit=None remembered in a save and with no other follower outfit setting mod you'll get a lot of naked peoples. This is unfortunately the only way i can make this mod compatible with other mods that change actor forms, without having to worry about compatible files or setting Outfit=None manually in other mods.
2) MAJOR THING:Also dismiss followers before removing the mod. Otherwise extra followers above the one allowed by vanilla game will be non-hireable with vanilla settings.