Acura 3.5 RL Manual page 1041

Overhaul
1. Remove the self-tapping screws and the vent/defroster
duct.
2. Remove the self-tapping screws and the pipe clamps.
3. Remove the self-tapping screws and the core clamp.
VENT/DEFROSTER DUCT
4. Pull out the heater core
NOTE: Be careful not to bend the inlet and outlet
pipes during heater core removal.
5. Assemble in the reverse order of disassembly.
PIPE CLAMPS
CORE CLAMP
HEATER CORE