Woog ...
My truck is a '52 1/2 ton and I'm just starting to do some of the small body work tasks.
I'm completely unqualified to do any bodywork or painting but I can tackle these small items.
An entry level hand pop rivet gun will run you about $15 and will be good for about 200 rivets, then something will break. My gun was about $30 but I've probably pulled 2,000 rivets over the last 10 years.
Use a 1/8" drill bit to remove the rivets and drill from the side with the indention if you can. You need to drill all the way through.
Good luck!!
shoeless