Without knowing or seeing it but have rebuilt many hydraulic rams and pistons I'll generalize it.
You will need a gland nut wrench or a well placed pipe wrench will work
just dont wile a clamp to tight or you will crush the cylinder. I use a pipe vise at my job. Wich is just a chain wrench. You have your gland nut on top where the ram or Chrome rod comes out. There you have a wiper seal which is the first seal, then you have your packing gland
in there and maybe a spacer. Some have one there some do not. As you pull your rod out of the cylinder you have another gland. Some are welded to the shaft some are not. If not welded the nut usually is tight so it does not come loose. Under that gland if it is not welded there many times is a o ring. On that gland you have your bearing (a hardened seems like plastic almost full ring with a split in it) there you also have a packing seal and most times a spacer with that packing seal. Sometimes a pia to get back in the cylinder without pining the seal or spacer. Use electrical
tape first to compress the seals
on the gland and use vasoline instead of grease to install the gland back into the cylinder. Also while having the rod out check the chrome if scoured or really nicked you may want to inquire about getting it rechromed if real bad. Of looks good take a 3m scruff pad and on the chrome scuff up the rod as to have just a light non directional finish so you do not wipe out your packing seal in the gland nut. You don't want to grovethe rod but lightly scuff the chrome rod.