I'm in a complicated situation where I have 2 children and 2 fathers neither are fit to care for my children in the event something happens to me. How do I take their paternal rights away, so that if something happens to me they'll end up with their godparents instead of the fathers??

Can you prove they are unfit? Can you prove they are a danger to their children? If not then you have no chance of taking their rights away. There are hundreds of threads on this subject read some of them and the sticky at the top of the page you will learn a lot. You can leave mention in your will that you want the boys with their grandparents but it if their dad's want them they will get them then the grandparents will have to go to court to prove them unfit.