"RicodJour" wrote in message
news:cd4e801d-b05e-485c-8fee-
This is the standard way of enlarging a hole. I use scrap 3/4"
plywood as it's less likely to create problems of depth, you can use
the ubiquitous 1 1/4" drywall screws to attach it, and the plywood
won't split with repeated use.

R


Or our friends at Lee Valley have this:
http://www.leevalley.com/wood/page.a...at=1,180,42316