The brake cylinder in the rear drum of a 93 ford ranger broke, how do i replace it

Remove wheel, brake drum, and brake shoes. The cylinder is the part the brake line goes into and it spreads the brake shoes apart when you brake.

Loosen the brake line but do not take off, unbolt the cylinder and then disconnect brake line. loosely connect the brake line to the new cylinder so you do not loose much brake fluid, bolt new cylinder in and then tighten the brake line.
Reinstall shoes. There should be a bleeding screw/grease head in the brake cylinder, loosen this and have someone step on the brake to bleed the line, have them hold the brake while you tighten the bleed screw. Do this as many times as necessary until brake fluid only with no air comes out.
Reinstall drum and tire, top off brake fluid.