missed the word gravel - read driveway apron - saw a concrete driveway in the picture & went with that
When I removed mine - the compacted stone underneath was nearly as hard as the asphalt - would have had difficulty removing it with a shovel or ax - but the hammer broke it up when going through the asphalt.
Good luck.
I'm curious. If the hammer broke it up nicely when going through the asphalt then how would you know that the compacted stone underneath was nearly as hard and would have been difficult to remove with a shovel or ax?