I have a 1979 chev 350 pu. No air. Any tips or advice on how to replace the heater core?

 

Sunup,
See attached diagram of the heater core. You will need to drain your radiator to avoid a big mess. This is also a good time for you to flush your cooling system before you install the new heater core as not to fill up the new one with all the junk floating through your system. The flush kits are cheap and show easy to follow instructions on how to use. Also check all your hoses for wear and softness and replace as necessary. Be sure to dispose of your used antifreeze properly.