I suppose it may be a dumb thing to ask, but do you have replacement bolts? Because if you have, then drill, if not, don't. Also, drill only if you believe you know what you are doing. I think the bolts material, at least on my older bike, is soft, the slotted kind on the inside side.
On newer bike, when I had them removed a while ago, they felt fairly light, almost like made from aluminum. But those were of newer kind, with hex wrench on both sides.