What is the best way to begin to remove a section of concrete slab for drain plumbing?

I am expanding a bathroom on the bottom level of my split-level house, which sits on concrete slab. I am about to begin removal of the section of slab to get to the drain plumbing. I scored the area to be cut with a diamond blade, it was dusty. Now I am about to begin removal of the concrete with a sledge hammer. I am guessing the first chunk of concrete will be the most difficult to remove. Does anyone have any advice/tips/trade secrets that would make the removal easier?