eburakboz

You can load "only" Kaidan.esp in Tes5Edit and go to armors on the left tab. Then find ragged trousers and ripped trousers and delete those entries altogether. Do the same for their corresponding armor addons and you are done. You can check which armor calls for which armor addon by looking at their Editor ID's. By doing this you delete his trousers (which apply a unique body texture for Kaidan) and now he takes whichever body texture overwrites your vanilla body (Better Males in your case). When you do this Kaidan starts the game as nude and you can give him whatever armor you want by his dialogue options. However you may notice a neck seam after doing this depending on which body texture you load. I don't know how to fix that part :( But neck seam is only noticable when he doesn't wear any armor so normally it shouldn't be an issue (if he doesn't go around naked all the time :D) Also you can make it less noticable by giving him a huge necklace like Amulet of Arkay. And I should add that these steps are valid for Legendary edition. But I don't think there would be any difference for SE.