WARNING: This page is about a different car, the 2024 Audi S6 and 2024 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
-- Disconnect the connector -1-.
Courtesy of AUDI OF AMERICA, LLC
-- Release the retainers -2-.
-- Remove the cap -5-.
-- Slide the suppressor -4- out of the housing -3- and remove it.