They are tricky the first time.
Push the center pin in about 1/8" until it 'clicks' then remove the entire rivet- it will come out easily. To reuse the rivets, remove the center pin and install it into the rivet with about 1/8" of pin sticking out beyond the rivet head. Insert the rivet and then push the center pin in flush to the rivet head.
Brian
I'm trying to remove flat panel under the running lights to replace those bulbs. How do the little button rivets come apart? Don't feel like having to replace those if they break, thanks