Remove the auto-tensioner.
Remove the tensioner pulley.

Install the tensioner pulley in the reverse order of removal.
Install the auto-tensioner.
Fuel Tank Draining
Remove the fuel tank unit.
Using a hand pump, a hose, and a container suitable for fuel, draw the
fuel from the fuel tank.
Reinstall the fuel tank unit.
...
Warm Up TWC Removal/Installation
NOTE: If the warm up TWC is damaged internally, inspect the under-floor TWC
for debris.
Raise the vehicle on a lift.
Remove the bolts (A).
Lower the vehicle.
...
Under-Cowl Panel Replacement
NOTE: Take care not to scratch the body.
Remove these items:
Windshield wiper arms
Cowl cover
Remove the bolts, then remove the under-cowl panel ...