I want to get the bed of my 01 dakota sprayed but the fender wells have some pretty big dents from the previous owner. What kind of hammer would i use to attempt to pound it back to shape? and can it be used directly on the inside of the fender or should there be a small wooden block or something simular on it? maybe heating it up a bit?

 

Do not heat it.
I use a hard rubber/plastic dead blow hammer to get worst of the dent because it will not put extra dings in that will need extra attention,then go to body hammers and dollies.