No special tools really. A pair of inside snap ring pliers to compress the retaining ring at the cylinder end. The tips need fit the ring holes.
A good vise to hold the rod while you loosen and tighten the piston nut. A block of wood to set the rod on when taking the piston nut off so as to not scratch the chrome.
Alternately, instead of a vice, you can leave the cylinder pinned to the bucket, remove the cylinder tube and keep rod steady to remove the piston nut.
Other than that, a good clean surface to work on.
Starting fluid works well to clean the parts of the cylinder.