how can i fix my heater core on 91 pontiac firebired?

I HAVE AN 86 CAMARO MINE WAS EASY ITS ON THE PASSENGER SIDE UNDER DASH MORE TOWARDS CENTER BEHIND DUCT WORK WHICH YOU HAVE TO REMOVE ITS EASY THEN THERE IS A SORT OF SQUARE COVER SCREWED TO FIREWALL INSIDE CAR UNDER THERE. THEN GO UNDER HOOD AND REMOVE TWO SMALL RADIATOR HOSES GOING ITO FIREWALL TOP PASSENGERSIDE BEHIND ENGINE THEN RETURN UNDER DASH AND PULL IT OUT AND REPLACE IT I PAID ABOUT 24.95 FOR MINE AND ABOUT AN HOURS WORK LOOKS LIKE A LITTLE RADIATOR

DAVE
April 2006