1967 front grill repair

Hi all. I have removed my front grill on my 67 Notchback. I'm polishing it now and will repaint some of it. I had to cut some of the mounting fasteners as others have and will need to install new fasteners ( others have sent me links to the best choice for replacement already). My question is this. can you install new fasteners without removing the rivets to get the new ones in place. does anyone have pics of how they installed new bolts or fasteners I can see?
I'm not experienced with rivets at all. Thanks in advance for any help.