The question you ask is too involved for a proper answer. You need to go to a car parts store, and get a repair manual for your car. They cost about $16.00 Or, go to a Public Library.
you should only have to take loose the heater hoses where they go into the firewall and of course the heater core itself
A "heater" or a "heater core"?
Locate heater control valve in a 2001 Honda civic
Buy a Toyota
WE DON'T KNOW!
The heater in the CRV Honda is not working . How do I fix this
how replace the ABS control for Honda pilot 2004
replace it
remove and replace.
Replace Thermostat
You may have a stopped up heater core, or it may be a faulty heater door or heater door control. Answer: Check coolant level. Replace thermostat. Check heater control cable, located under small cover above the the passenger floorboard, near the console.
How do you add freon to a 1999 Honda Passport