If you don't have or want to get coin mechs, or you want to use any kind of coin/slug/token, you can add an extension to the coin chute that directs all coins across the microswitch lever. I couldn't find the project where I'd seen this done, so no pictures to share, but I believe the guy just bent some thin sheet metal into a kind of tube and glued it to the chute. You could probably do it even easier and cheaper with some tin foil, carboard, or paper.