Potty Training Nightmare

I have never heard of a child as stubborn as mine when it comes to potty training. We signed Michael up to start preschool this fall, but of course he needs to be potty trained to go. He's excited to go to school, but much less enthusiastic about going on the potty. I have tried every tactic known to man and have resolved that "waiting till he's ready" is a joke. I'll be wiping that boys bottom till the day he leaves for his mission. He's capable, just STUBBORN!!! I'm probably cruel to "force" this on him, but all I can think to do is fight stubborness with more stubborness and hopefully win the day.