Body Molding questions

Depending on how curled the ends are if the moulding is salvageable or not.
After you've remove the molding try applying some light heat to the ends to see if they'll lay down flat or not. If it lays flat you're good to go if it doesn't lay flat you probably need new ones because the new double back tape won't stop the ends from curling again.
If you can get the ends to lay flat then remove the thin metal strip that the double sided tape was originally attached to and then clean that area throughly and then reapply new 7/8" double sided tape to the molding. Clean the door area throughly also where you'll place the moulding back on the door.

I have used acetone on a swab/shop rag to clean the body and molding with it in place. Be careful with the acetone since it will dissolve or damage paint it you get it in the wrong place. After giving the acetone sufficient time to evaporate, I used some Super Glue to stick the molding back in place. You may have to find some way to hold the molding in place while the Super Glue sets, but this will work.