The easiest way is with a "C" clamp.
NO! Brake Calipers are what compress your Brake Pads on to the rotor which turn simeultaniously with your wheels.
No need to rotate the front caliper pistons as you compress the front calipers. That process is only for the rear calipers because of the parking brake mechanism.
A 1993 Mercury Cougar takes ( DOT 3 brake fliud )
the piston on the rear calipers will turn in a clockwise motion and that is how they retract.
are u trying to change them?
Remove the tire and wheel from your 1994 Mercury Cougar. Remove the brake spring and brake caliper. The brake shoes will come off.
The rear brake calipers screw back in. This is because of the park brake. There is a tool that you can either buy or rent from one of the larger parts stores.
The brake and clutch fluid systems are supplied by the brake fluid reservoir ( according to the 2001 Mercury Cougar Owner Guide )
On a 2000 Mercury Cougar : The brake fluid reservoir is also the clutch fluid reservoir
Your brake light switch under your pedal is brobaly stuck
The calipers on a Mazda 6 turn inwards you don't push them to compress them.
Remove the tire and wheel from your 1999 Mercury Cougar. Remove the brake spring and the break caliper. The brake pads will come off. Reverse the process to install the new brake pads.