The steel in my C-stands is pretty robust. If any were dented as you describe, I think the dent puller route would work, but you'd have to heat the affected area with an acetylene torch in order to actually move it, and if it's chrome plated, heating to 1200-1500F might not be the best thing to do with the chrome. Not only will it ruin the chrome, but it may release unhealthy vapors as well. It might just be easier in the long run to replace the tube.