As an ex-mechanic (well,I still work on my stuff),my first inclination would
be the air chisel.This is what they were made for!
You can remove a lot of stuff with one those babies!
Probably take less than 3 minutes to remove all three rivets.
Remove heads,drive out with hammer and punch.
Next up would be drilling out rivets.Guesstimate the size of the hole,
go one smaller and have at it.Finish with hammer/punch.
Last would be grinder.While effective,IMO,would take too long,dangerous
(sparks) and general P.I.T.A(You ain't lived until you've set
your pants on fire!!!).Grind off head,hammer/punch.
Possibly use a thin cutting wheel on 4.5 grinder,carefully cut heads off,hammer/punch.
Good luck.
WEAR EYE PROTECTION!!!
