you could try steam to get these out. the dents look fairly "sharp" so i dont think you'll fix it completely...
Set steam iron to hot, place a damp rag flat over the area, put on the iron and hit the steam button, give it a short moment then lift off.
You may have to do this more than once, check after each time, all the best.
there are other methods of doing this - check google and youtube as well