Yes he can - however it is sometimes a matter of interest - and if pulling the heater core requires pulling the dashboard or much of the heating duct work - it is a real PIA do do correctly without experience (interior pastic bits tend to break and deform without the correct toolset practice and factory service manual).
It can be a seriously tough job. Much has to be removed to access the core and then add a part that may be corroded in pace.
It sounds like he is capable. Maybe he needs an incentive such as his favourite pie.
So he has built and rebuilt transmissions. On a Honda Toyota and Chevys and replaced engins as well. so don't you think he can do a heater core replacement. Or is this job in a league of its own.
