By asking acablest to do it.
how to replace a heater core on a 2003 Nissan Altima 2.5
look to the left of the battery for a cord
The heater core is located underneath the dashboard on the passenger side and a lot of the dash components will have to be removed. This is a fairly complicated repair and I recommend getting a book so you know how to do it properly.
there is a relay the needs to be replace in the heater which cost about 50 dollars and you need to take out the glove box and it is easy to replace. takes about 1 hour or less.
Under the dash behind the glove box on the passengers side........
there is an electrical panel box in the engine conpartment..take the cover off and read the inside cover and look for heater relay
you may have a bad thermostat,replace and see.
You pretty much have to remove the entire heater box under the dash on the passenger side
To replace the heater core in a 1984-1989 Nissan 300ZX, first disconnect the battery and drain the coolant. Remove the dashboard and the center console to access the heater core. Detach the heater hoses from the core, unbolt it from the housing, and then install the new heater core by reversing the disassembly steps. Reconnect all components, refill the coolant, and check for leaks.
By the clutch pedal two screws and a plug
yes, see toms z31.com
The average cost of labor to replace a heater core will vary from dealer to dealer. The national average is around 105 dollars per hour.