Pull the mag spring as stated. Take the barrel off, Get a small screw driver and press on the magazine latch, located just under the port. Has a little square looking lump that sticks out of the edge of the magazine tube (to see it out of the gun it is a long spring steel piece approx. 6-7" in length, smooth for the first 3 inches and then has a rib on it that runs toward the end. at the end there is a sort of jagged section that has a small dimple that fits just to the side of the tube to hold it in place). Press in on the square latch part and the shells should pass by it. Would be a lot easier to show you but I am doing the best I can, to describe it. Just tore the 870 down and have the piece laying in front of me.