Replacing the heater core in 2000 mazda b3000

From Haynes Repair Manual #36071, Ford Ranger Pickups 1993 - 2005 and Mazda Pickups 1994-2005 B2300, B2500, B3000, B4000: (1)Disarm the airbag system; (2)allow the cooling system to completely cool down; (3)using a thick cloth for protection, turn the radiator filler cap to the first stop; (4)step back and let the pressure release; (5)once the pressure has been released, completely drain the cooling system; (6) working within the engine compartment, loosen the ****,ps on the heater hoses at the engine compartment side of the firewall, twist the hoses and carefully sepseparate them from the heater core tubes; (7)plug or cap the heater core tubes to prevent coolant from spilling into the passenger compartment when the heater core is removed; (8)place a plastic sheet on the floor of the vehicle to prevent stains if the coolant spills; (9)remove the instrument panel; (10)remove the PCM heat sink and ground strap; (11)remove the heater plenum chamber; (12)separate the heater core from the heater plenum chamber; (13)installation is the reverse of the removal with the following additions; (a)fill the cooling system; (b)run the engine, check for leaks and test the heater