Secure the master cylinder in a vise with soft jaws, level and stable
Fill the reservoir with the correct brake fluid
Install bench bleed fittings or short bleed tubes into the outlet ports
Route the bleed tubes back into the reservoir so the ends stay submerged in fluid
Slowly push the master cylinder piston in with a screwdriver or pushrod
Release the piston slowly and let it return fully
Repeat the stroke until no air bubbles appear in the fluid returning through the tubes
Top off the reservoir as needed to keep the ports covered with fluid
Keep stroking slowly to avoid introducing new air
Remove the bleed tubes or fittings while keeping fluid loss minimal
Cap or plug the outlet ports immediately
Install the master cylinder on the vehicle and connect the brake lines
Bleed the brake system at the wheels if required