Player model problem

Am I doing something wrong here? I really need help in putting these playermodels into my player settings. They come up, but whenever I try and change into them they always come up as Kleiner. Please help me descriptively as you can with a tutorial on how to do this PLEASE.
P.S. I will worship you
no jk jk jk

What models you trying to use?

Almost every model I try to download!

Well we need some links just to check

im having the same problem with theese models and idk where to put them so they appear