You have a few hours of hammer work it looks like, slide hammers work good on a flat surface but when working the lines you almost always have to work it by hand. I am sure you know how but just for kicks I will go through it.
Cut yourself a nice peice of 2x4, about 9in. You will use this by holding it firmly on the outside. The soft wood absorbs the blow and helps keep the shape your going for. Useing a hammer made for body work start with the steel side intill your close to shape, switching to the rubber side for finnish shapeing. A flat peice of brass is handy to remake lines and angles. Rember it is better to tap it 100 times than smack it 10 times. You want this slightly below the finnish plane of the fender.
Useing a sander with course paper smoth out the bumps, switch to a fine grade paper to rough the surface. Clean and prep your surface, and skim coat with bondo, make sure you apply extra so you can tweek the final shape wile sanding.
Sand
Open a beer/ smoke a bowl and walk around looking at your work, change the lighting, stand infront and look at the lines, mark where needs fixed, go to bed and come back the next day. That step is importaint. After working on a spot for a few hours you will become blind to your mistakes. I know from experience that if you don't take you time and make it near perfect you will see that spot every time you walk up to your car. Then it is down to paint.....I pay people to do that, always orange peel mine so I am no help there.
