I do bodywork for a living. At our bodyshop sometimes we get a paintless dent removal guy to come in. PDR ain't easy, it takes skill and alot of patience. If you have no experince with it I don't recomend you even try, you'll most likely damaging the paint. Look around for a pro to do it. If you want to give it a go what you need to do would be get access to the back of the dent and gently pry it up with a pick. You need to do this in a well lighted area so you can use the reflection off the paint to see what you doing. after this you use a plastic punch and gently tap any high spots down. Theres alot of other tricks as well. After you'll need to polish the area. From what I've seen, PDR never gives you 100% perfect results. There's always a ripple. If you want perfectly straight, get it fixed at a bodyshop and repainted.