Locking License Plate How Do I Loosen Really Rusty Bolts On License Plate?

How do I loosen really rusty bolts on license plate? - locking license plate

I have to remove screws from my car number plates, but they are really rusty. I am also very limited tool, has only a few small screwdriver and a hammer. My uncle has a torch, but I doubt they could use me. I thought I could bring down the gap around the screw, and adjusting to the new car with a washing machine, but it might take some time. In addition, a screwdriver into the slot lock is not too rusty over. What do you think I should do?