Assuming you have the remover firmly clamped to the bottom bracket cup (an M8x1.0 bolt about 40 mm long threaded through the Park BBT and into the spindle threads is an excellent way to hold it in place) and are turning it the right direction, I've used a rubber mallet to pound on the wrench handle to break the cup loose. Have the bike resting on it's wheels on the ground as you don't want to damage the frame by having it clamped to the repair stand.