The pin for the cocking arm is different for the two versions and I fitted a roll pin when I was playing with one recently.
Remove sights and remove the 2 screws at the forend of stock and the trigger guard one. Carefully lift action from stock as trigger pins can fall out. Remove bottom pin and trigger should drop a bit. Remove top larger sear pivot pin and the trigger,trigger spring (bent wire thing) and the sear should come out together. On earlier version the trigger stop pin will also come out. REmove plastic end cap. Knock out cocking arm pin and remove cocking arm. (note piece of plastic In cocking arm on early version to stop pin moving). Break barrel and push in barrel plunger and knock out barrel pivot pin. Remove plunger and spring and then the barrel from the jaws. Place cylinder jaws down on piece of wood and using your bit of tube (SEE 1ST POST PG1) push down on guide and remove cylinder pin. Ease pressure and remove guide, spring and piston. The piston head may be loose if the piston buffer washer has rotted and crumbled (they all do). On the late version the retainig circlip may have broken and the piston will come out and leave the head behind! GO TO NEXT POST