If there's enough of the rivet left, reinsert it and try to flare the end as best as possible. I don't think it's strictly needed, but I may be missing something, so you may as well put it back just to be on the safe side.

You can take this time to remove the protective tape, but I also put down another piece on top of the rivet on both sides to keep the sharp edges from scratching things, and to help hold the rivet in.