refinishing 8' bedsides on fleetside bed

[gmc1971harwich]

im trying to take the dents out of my bedsides, but i cant find a way to reach them from under the bed. if i unbolt the bedside, is it going to separate the inner from the outer bedside? do u guys have any helpful tips for about pulling dents out of the bedsides? theres a 1/2" layer of bondo underneath the paint covering up some dents and i would like to take it all off and do it right, and pull the dents out. il post pics maybe tomorrow.