Start by removing the cylinder collar, then remove the cylinder shaft from the casing by grabbing the end of the shaft with vice grips and hammering down to remove the shaft, then remove the old worn o-rings and scrapers with a small flat head screwdriver OR A ORING REMOVER TOOL, then clean the cylinder and mounting pad where the orings were with brake clean , then lube with oil, then replace with new o-rings being carefull not to tear the new o-rings, then insert the cylinder shaft back into the casing lube with oil first, then tighten on the collar using pipe wrenches or a vise and reinstall back onto the vehicle!! Follow the pictures below it should help!!