References for Repairs of HVAC

[DJ_Baar]

I will be taking-out complete HVAC because it has not been working (previous Owner removed tubing and in-work). I got the assistance to explain best way to remove (hood and inner fender 1st). Now if you guys know best POC (point of contact) references to upgrade to R134a while I am at it (availability of refrigerant and DYI) and any other helpful advice it is appreciated. (I will replace poa valve with correct new one.) I plan to take heater core to a radiator shop, can I do same with A/C evaporator or just replace one or both? Thanks in advance.


R/
DJ