you need the "gland nut" and a packing kit
if youre gonna take it apart and buy the kit you should replace the seals on the piston itself too (remove the ram)

whats your mast number and overall lift height? (lift height is on the data plate)
from what i see, it just screws in just like other cylinders
youll need a spanner wrench
look to see if you can get a number off the cylinder itself (stamped in the metal)

your mast number should start with A753
the lift height should be either 85.5" or 97.3"