Your clutch disc is most probably frozen to the flywheel. 2 options. Start the car and make sure it gets up to operating temp. Turn off engine, put in gear and start on key and drive off, it will loosen off eventually. Or do the same jack up rear end, with car in gear and running. Drop onto the ground and the shock will free off the disc plate.
M/C 5/8", slave 3/4.