Buy, borrow or rent a stud gun and pull the dents and fix it. If no stud gun, use self tapping screws and a slide hammer. When done, weld the screw holes shut.
I have never used one but the kits where you zap the studs to the dent and then use some kind of bar where all the studs hook onto threaded
Bolts seems in the videos to be just the trick for a straight dent like this
Someone with more experience will hopefully chime in and explain what I'm taking about
What about rust? Would it be a good idea to make patches? My drivers rocker has rust on a flat spot of it. The passenger has even more but on the bend.
If you can, take a peak inside from one of the ends. The ends of mine were compromised and each rocker had about five pounds of rocks and dirt. If you can get that stuff out (shop-vac with small hose) spray it with some type of rust inhibitor. Otherwise it looks pretty good and definitely worth keeping.