It's really really simple, but if you want I'd be happy to help you install it. Basically the handbrake just interrupts the rear brake circuit. The master cylinder is just like any master cylinder.
Straight through from the reservoir port to the outlet, but when you pull the lever the piston inside slides past the inlet port and forces fluid out the outlet to the rear brakes. When you're not pulling the lever, the fluid just flows right though the thing for normal braking. Also the seal on the piston is like a one-way valve so fluid can go around it from the brake pedal, but not backwards.
HERE'S THE MOST IMPORTANT THING:
When/if you buy a hydraulic handbrake, do not EVER pull the lever before you have it installed with fluid in the lines. I put one of these on my friends S14 years ago (the White RHD one at Hialeah Dec 2004) And everyone at the shop had played with it while it was on the shelf. It destroyed the seals inside and it never worked properly.