Very easy indeed. Get a longish socket from a wrench kit that just fits your bore. Shim one side with electrical tape if it's not quite tight. Position it under the dent (doing so will remove the dent partially anyway). Heat the area around the dent with a propane torch, easy does it you are not trying to melt solder! Tap the area immediately around the circumference of the dent with a brass hammer. Lightly does it. You can put a piece of crocus cloth, rough side toward hammer, over the area to avoid marking the finish. You are pretty much done. You can hone the bore a little in that area, and if you are really retentive, you can reblack the bbls but you shouldn't have to.
