door trim how to .plz

can anyone tell me how u remove & replace the rubber trimm (seal) that runs along door panels on the outside of the doors. this is on the out side of the door where door meets the window glass . a garage has removed it & not put it back in a nice flat manner like it should. id rather not take it back the garage as it seems to be run by chimps ,thanx.i think they just pull off but i dont want to risk it without knowing sum info first.heeeeeelp plz