Windshield Trim Installing Help

1970 Dart Swinger Trying to get trim to snap in along roof been using the palm of hand not working.Bought new clip set from RT Spec there are 4 different clips Tom from RT says they go in top on outer edges 2 each side. Thought about rubber mallet but kind of worried on damaging something. Sides snapped in no problem Bottom all but 2 snapped in. Any Ideas??