[metal] how to embiggen the hole?

[tenders]

I don't know whether it's a good or bad idea to make the hole bigger, but it isn't a difficult job. A cobalt bit and some cutting oil (WD-40 in a pinch) sprayed on it before and during drilling will make it a relatively straightforward process. I would use a drill press to do it, but a hand drill with a "mini drill press" attachment might be OK.

http://www.amazon.com/Wolfcraft-Attachme...B000JCIMEA