I found this on a website. Hope it helps. By the way, I spent over an hour looking, so it's pretty hard to find info on the subject. Anyway, here it is:
Q:: Is it possible to change a token slot machine over to a coin operated machine?
A:: Yes you can convert a token machine to coin, you need to convert the hopper to the coin that you are going to use, and change the coin in the coin comparator, and the coin head.
If the machine accepts bills you will need to change the denomination in the program so that you get the proper number of credits for the bills that are inserted if its a quarter you get 4 credits for each 1 dollar bill etc.
"I am in so far in blood, that sin will pluck on sin" - Richard III