Lift the vehicle, and support it with jackstands.

Remove the A/F sensor (sensor 1).

Remove the secondary HO2S (sensor 2).

Remove the bolts (A), and the nuts (B).

Remove the TWC (C).

Remove the bolts (D), and the covers (E).

Install the parts in the reverse order of removal with new gaskets (F) and new self-locking nuts.