I think you already asked that in another post and it was answered. 4 screws, two on top and two on bottom, the brake will slide off to the "passenger" side of the car when the screws are out and the disc will slide off the shaft with it. to reinsert the brake assembly, you almost have to pry the transmission up with a small flat screwdriver to spread the gap so you can shove the 'bottom' part of the brake assembly back in (with the new disc floating inside the brake caliper).
All this is assuming you need a new pad.
With the car off and one wheel braced, can you spin your servo in 'brake' direction and lock up the 'free' wheel? (trying to spin it by hand)
If that locks the free wheel, your brake disc and caliper are fine, you're just out of adjustment. You'll need to adjust for a little more tension on the brake linkage. I don't know if all GTs have the threaded brake linkage like mine (got mine used), but if you do, just thread the nut a few spins at a time towards the servo. This will slowly adjust more tension onto the brake.
whew... that was a mouthful and it SHOULD have been posted in your other thread but I'm too lazy to navigate... mods will probably merge them.