Don't even think about it until it is time to replace the chainrings. If you drill out the bolts and the replacements don't fit exactly, ie if there is even a little slop, the crankset will do a slow death as the blot holes elongate. Standard crankbolts holes are 10mm exactly. Chainring bolts are also. Snug fit, not the clearance fit of the usual bolt and hole.
I'm guessing those rivets are doing a good job of being tight, no play at all. Don't disturb them until you have to!
Ben