Insert an 6-8 inch small diameter wood dowel in the space between the barrel hook and forend iron. The size of dowel will depend on the gauge of the gun, but use the tightest fitting dowel possible. Place the barrels muzzle down on the floor using a piece of carpet as a cushion. Push the dowel toward the floor to create the space normally present if the barrels and forend were mounted on the action. Holding this position, reach down with the other hand, rotate the roller latch forward, and using the index finger (or have an assistant) pull off the forend against the tension of the J spring.