If this is for a SEASTAR, before I added a chemical that softened the seals, I would spend $100 and get a seal kit, comes with one for each side of the ram, and a tool to remove them with. Bleed and yer good to go. Hardly any fluid comes out when you remove the end seal, just have a quart of fluid on hand to top up for the bleed process.
Or was this for the hydraulic motor tilt?
EDIT: BTW, a new ram cylinder is about $500.