Raise the vehicle on a lift.

Remove the bolts, and separate the under-floor TWC from the warm-up TWC.

Remove the bolt (A).

Remove these parts.

Remove the A/F sensor (Sensor 1).

Remove the EGR pipe.

Remove the cover (A).

Remove the bolts (B) and nuts (C), then remove the WU-TWC (D) and the gaskets (E).

Install the parts in the reverse order of removal with new gaskets.