We generally rebuild / repack the cylinders while the base is still attached to the machine. Unless there is damage to the barrel or you are replacing the cylinder all together, then there is no reason to remove it completely / all together. I would loosen the hydraulic lines once you take the pin out on the lifting arm, because then it will lay down on the frame of the machine, making it easier to get to them. It might be wise to repack both lifting cylinders at the same time. That way you are not repacking a leaking cylinder the very next week. It is just the way I do it.Lift the boom up and put the boom lock on the opposite cylinder and lower the boom until it's resting on the lock. From there remove the pins and hoses then lift out. I find crowfeet sockets work pretty good for getting at the hoses.