Hydraulic cylinders have the same basic internal component structure. Their exterior assemblies are also similar. Retaining rings are common mechanisms that secure components on the rod end of many hydraulic cylinders.
Most hydraulic cylinders are closed and sealed at one end. The piston rod extends from the other end and is held steady and in place by an end cap, bushing, rod guide or other such device. A retaining ring of some sort often secures this device.
A snap-ring is one of the most common retaining devices. Removing it requires a special tool. A wire lock-ring can also hold the rod end of a hydraulic cylinder. It may not need a special removal tool.
Remove a snap-ring by inserting the nose ends of snap ring pliers into the holes or notches of the cylinder's snap ring. Close the pliers to compress the snap ring enough to remove it from the groove in which it sits. Wire lock ring removal procedures may vary, but prying it from its lock-ring hole with a screwdriver and rotating the rod end or bushing can remove the wire lock-ring on some cylinders.