Subaru Legacy 2004 Service Manual page 3392

Heater Core
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
11.Heater Core
A: REMOVAL
1) Remove the heater and cooling unit. <Ref. to
AC-36, REMOVAL, Heater and Cooling Unit.>
2) Remove the screws and remove the heater core
cover and pipe clamp.
AC-00917
3) Remove the heater core.
B: INSTALLATION
Install in the reverse order of removal.
AC-30