Start with securing the mounting flange of the brake master cylinder with a bench vise, then remove the reservoir cap and diaphragm. install suitable fittings to the master cylinder ports. Install transparent hoses to the fittings installed on the master cylinder ports. Route the hoses. Fill the master cylinder reservoir to the halfway mark. Be sure that the ends of the transparent hoses running into the master cylinder reservoir are submerged in the brake fluid. Use a smooth, round-ended tool, to depress and release the primary piston. Release the primary piston until fluid flows from the ports with no air bubbles. Remove the hoses from the reservoir. Install the master cylinder reservoir cap and diaphragm. Remove the fittings with the hoses from the cylinder ports. Then remove the master cylinder.