You don't need to be a bodybuilder -- nor do you need to rely on one -- in order to clear large rocks from soil and move them out of the way. Fortunately for even the least muscle-bound gardeners, physics and a few simple machines work well as stand-ins for raw muscle power with less risk of injury. Although a large stone in the soil is undesirable, you can save these large rocks and put them to use elsewhere in the garden, using similar techniques to move them to their desired space.
Remove all the soil from around the rock until you can easily access the base. Set the soil aside so you can back-fill the hole later.
Lay a piece of sturdy plywood -- 3/4- to 7/8-inch thick -- on the ground beside the rock and hole. The plywood should be large enough that the entire rock can comfortably fit on it.
Place a brick or smaller stone in the hole directly beside the stone and opposite the plywood.
Wedge a long pry bar between the brick and rock. Pull back on the pry bar handle, using the brick as a fulcrum, to pry the rock out of the soil. You may need to reposition the brick and pry bar a few times before the rock will come loose. As you pry the rock free, have a helper flip the rock over onto the plywood. Adjust it so it's centered on the plywood. (You may need to stabilize it with smaller rocks or clumps of dirt to prevent it rolling off the board.)
Lift up one end of the plywood and place a piece of 4-inch PVC pipe or iron pipe under the end so it resembles a ramp. The pipe should be slightly wider than the plywood. Use a helper and the pry bar to lift the end of the plywood.
Push the plywood forward along the pipe until the pipe moves to the center. Place a second piece of pipe under the front of the plywood, exactly where you put the first piece before moving the board.
Push the board along the two pipes until both pipes are equal distances from either end of the board. Place a third pipe on the ground in front of the board, spacing it the same distance apart as the distance between the first two pipes.
Push the board forward onto the pipe placed in front of the board and keep pushing until the rear pipe -- the first one you used -- comes out from under the board and the board is able to balance on the two pipes below. Stop and move the rear pipe to the front of the board. This works much like a conveyor belt, except that you must reposition the rollers yourself. It might take a while to get to your destination, but the pipes do all the work and save heavy lifting.
Lift the plywood to dump the rock in its new location. If you stop replacing pipes at the front of your makeshift conveyor, the single pipe at the back creates a ramp so you can lift the board to tip the rock off.