[Latitude 28]

I've had to do this before and usually try to attach a piece of plywood so the pilot drill can get a bite for the hole saw to start.
This looks like a good solution, use a hole saw the same size as the existing hole as a guide with the larger hole saw mounted above it:

Forest, That's the beauty of this forum, with so many individuals from so many different  backgrounds and the willingness to share....it's amazing the results!