I am in the process of restoring the doorstep on my Victorian terraced house. It has been tiled over at some point, which is not to my taste. I have stripped back some of the tiles, which took quite a long time as they were well and truly stuck down! Anyway, when the tiles were added the height of the step was increased by what looks like concrete and so I need to remove this with damaging the original step underneath, which appears to be in fairly decent condition. See attached photo. Does anyone have any ideas how I can remove the concrete without damaging the original step?