The document provides instructions for installing and removing parts of the main hydraulic pump, selector valve, and control manifold on a 305E Mini Hydraulic Excavator. It lists the required tools and parts and includes illustrations and step-by-step instructions for assembly and disassembly. Key steps include installing bearings and seals, connecting hoses and harnesses, and removing manifolds and valves by disconnecting connections and removing bolts. Safety warnings are provided to prevent injury when handling spring loaded parts.