No heater in the middle of winter????

O.k. I have a 92 Chevrolet Camaro RS, V8, 305. Heater quit working about 2 months ago, replaced the relay and motor. Ended up at the heater switch and the resistor. Only thing is is I don't know how to put the parts in. Looked in the book, but I've only learned how to take apart the dash and the shifter. Maybe someone can explain what has to come off and what doesn't? Someone please help me....It's getting a little chilley driving down the highway with my window down!
Thanx
Roxy