To remove and install the master cylinder, first disconnect the clutch pedal arm from the pushrod and the clutch hydraulic line from the master cylinder, taking care to prevent brake fluid from contacting painted surfaces. Next, remove the nuts attaching the master cylinder and pull it along with the pushrod toward the engine compartment. For overhaul, begin by removing the master cylinder from the vehicle and draining the clutch fluid from the reservoir. Then, take off the boot and circlip to remove the pushrod, followed by the topper, piston, cup, and return spring. Clean all parts using clean brake fluid and inspect the master cylinder and piston for wear, corrosion, and scores, replacing parts as necessary; light scoring can be addressed with crocus cloth soaked in brake fluid. The cup seal should generally be replaced with each disassembly, and the cup should be checked for wear or damage. Inspect the clutch fluid reservoir, filler cap, dust cover, and pipe for any distortion or damage, replacing as needed. Lubricate all new parts with clean brake fluid and reassemble the master cylinder in reverse order, ensuring the cup seal is carefully reinstalled to avoid damage. After installing the master cylinder, adjust the height of the clutch pedal, fill the master cylinder and clutch fluid reservoir, and bleed the clutch hydraulic system.