Vinyl trim help

Hey guys, sorry im new to all this. When I bought my chevelle It had the vinyl top mosly done. The only part left to be finished on it is the lower rear part and the back as you can see in the pictures. I have some vinyl trim pieces for all of it except for the corner (the circled red part in the picture)...where could I get that. Also, how exactely do I get the trim pieces on....I have green lines on the pictures of where there are studs I think in the car....how does the vinyl trim stay on those and do I just glue the lower vinyl top to the body and slap the trim on somehow after? Like I said, im new to all this....I really appreciate your guys help thanks.