It's not really very hard. If you feed him on a regular schedule, wait 20 minutes after he eats, get him a book or a toy and set him on the potty. Don't let him up until he goes. He will quickly figure out that the sooner he goes, the sooner he gets off the pot. He will also figure out the eating/potty connection. This will require a little effort on your part, but should only take a day or two for him to get it. Talk to him and repeat over and over, "if you go potty, you can go back to cartoons or whatever he was doing. Consistency is the key. BTW, if you bribe him to go to the potty, you will likely wind up bribing him for everything. That is a bad pattern to develop. JMHO
Ronnie