Get a stack of short 2x4 and 4x4 about 2" long as well as 2- 6ft pry bars. You would be amazed what 3 people can do with levers. I have moved 10'x10'x1' concrete slabs around with no problems this way. Work the rock up, and place the liner my moving the cribbing to allow you to unroll a liner underneath it. Use good protection so as not to damage the liner, old carpets and plywood work well.