Put on safety glasses, long pants, a long-sleeved shirt, a dust mask, a hat and work gloves. You will need a helper to assist you with this project; your helper should wear the same safety gear that you do.
Find the outer edge of the cement or concrete slab. Dig out few inches of soil from underneath the edge of the slab with a pick. Remove just enough soil so that you can fit the edge of the pick under the edge of the slab.
Have your helper hold the pick under the edge of the slab and pull the handle toward himself to raise the slab slightly.
Hit the surface of the slab with a sledgehammer about 24 to 36 inches from the edge being held up by the pick. Continue hitting the same spot with the sledgehammer until the slab breaks.
Smash the piece of slab that has broken off with sledgehammer into smaller pieces so you can remove them. Remove the pieces with a shovel and discard.
Continue using the pick and sledgehammer to break away the edge of the slab 2 to 3 feet at a time until you remove as much cement or concrete as you wish. Remove the debris with the shovel.