Usually the packaging tells you the recommended drill bit size for each toggle. Also there are a few websites that give the drill size for different toggle sizes. When in doubt, start small and work up. You can always drill the next size up, but you can’t go back. To install the bitin the drill, you’ll have to check your user manual, but usually you spin the chuck, In some cases, a special chuck key is necessary, and usually stored on the drill somewhere. Most newer drills are keyless now though.