Forget the drill, you'll need too large a countersink to do the job. Simply use a bench grinder to grind off the retaining flange and pop off the chainring.
BUT, before you do that, think about how you'll attach it's replacement.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.