The master cylinder is in the vise(with padding), the piston is pushed down with a small screwdriver(propped on top of the vise), and I could probably get the circlip out with ordinary snap ring pliers....... but........ the MAC guy quit a while back and my small pliers are short a tip. dang.
The pliers sold for this purpose are nice....... but...... I don't feel like buying one right now. The price of the pliers would pay for the master cylinder kit and a caliper seal.
This project requires a pair of cheap pliers, 2 hardened concrete nails, drill and grinder.
First attempt: used 2-1/2" nails - too long and springy - had to squeeze them together with needle-nose to get the ring out.
Second try: used 1-1/2" nails - ring comes out without further assistance.
Dug around and found a pair of old cheap pliers. Nails measured .144" . Drilled pliers through with #27 (.144") bit, then almost through with #26 . Ground ends of nails to a cylindrical shape tip. Hammered nails into pliers and ground some more from sides for clearance.
Yeehaw it works!
Happy trails.