Mine had the same problem the P/O musta got one of those little snak paks of screws from wally world ta put em back on wit. Now they look great, of course my OEM rockers are up overhead in the loft.... But when they were on the car and I replaced the screws wit the GM originals and used the kit shown. My tool of choice were the needle nose visecripts. They were justa tad bit easier to manage while tryin ta hold me tongue in place...    

I too have BTDT.  Funny how just one little screw/bolt can turn what should have been a quick and simple job into hours of frustration.  Now days,  I've learned to pre-treat any fastners on mine with penetrating lube before I even try to take it apart.   Its helped alot !