As long as it's unreinforced 4" and you don't/can't use equipment breaking it up with sledges and long pry bars is not too bad. If you have to rent a breaker just rent a electric.....they do the trick and cost a whole lot less.I'm removing and replacing about 60' of 4" sidewalk. I'll be removing it by hand. Is an air hammer the best way to go here? Or is that over kill?