There are a bunch of free drag and drop utilities for the Mac to do this. I use
Suitcase to manage my fonts and it is part of it so that is what I would use.
Back when I was still using Mac Classic OS I used a porgram named
Fontographer to convert anytype of font to anything, it is also used to create fonts from scratch.
Since I'm running Mac OS X I no longer need to do this since I can use Mac fonts, PC fonts, *nix fonts, and NeXT fonts without needing to convert them.