How do you get a rusted ball off a trailer hitch?
Removing a Rusty, Stuck Ball Mount & Hitch Ball
Try spraying the areas around the receiver opening with WD-40 and then use a rubber hammer to help knock the ball mount loose. Once it's free you can either pull it out or gently tap it out with the hammer.
How do you remove a stuck hitch pin?
If you heat the hitch and pin using a torch a lot of times it will break the materials free and you can use a hammer and punch to remove the pin. Use a Sawzall with a thin metal cutting blade to get between the receiver and the stinger of the rapid hitch to cut the pin.