Remove the two trigger guard screws and the trigger guard. Remove the two screws that you can now see that hold the action to the frame. Watch out for the trigger spring as you lift the action out although it may remain in the frame. Undo cocking arm pivot lockscrew and remove pivot. Undo barrel pivot lockscrew and remove barrel pivot. Lift barrel and cocking arm away. If you need to change the breech washer do it now. Remove sear spring and then the trigger and sear pins and the trigger and sear. You may have a bit of trouble either getting the pins out or back in as they are sometimes popped with a centre punch to retain them. Push endcap against a piece of wood and squeeze together the tangs of the retaining circlip and then let off pressure so endcap comes away with circlip and probably mainspring. When you pull the piston back to remove it, the cocking arm should lift out once its far enough back in the cocking slot. Remove piston and change piston washer if needed. The last one I did was leather, held on by a small countersunk screw. Clean and lube everything and place piston in cylinder so you can get cocking arm in and then push all the way in. Go to part two.