You can do what I did. I've had a few small dents from people not knowing how to open their car door next to some one's car. I got a heat gun, and a can of spray air you can find in computer stores. It's called duster.
Apply heat from the heat fun, or hair dryer till it gets pretty warm. Quickly switch to the canned air, and spray the dent till it pops back out. It depends on the dent, and on the spot. It won't work every time on every dent.