There are a few different ways to racoon proof your garbage cans. One way is to tie the handles of the garbage can to a secure object so that the racoons can't tip it over. Another way is to put a lid on the garbage can that has a weight on it, or is otherwise secured so that the racoons can't lift it off. Finally, you could also try putting your garbage cans inside of a larger bin with a lid that the racoons can't get through.