I would have to go back and re-read but as long as the box was all the way to the left I believe the entire piston assembly should just pull out. Do not thread the shaft out. I don't know, it sure wasn't that complicated as long as you follow the directions and the order of disassembly. I have done it on a 1986 and 1992 box with ease.
if you keep it to the left, it will keep them in, i was cleaning mine and turn it to the right and spilled mine. feeding them back into the 2 piece tube was the only way i found to get them back in. been on several rides and it works great except for a little pump roar.
wade