WARNING: This page is about a different car, the 2022 Audi SQ7 and 2022 Audi Q7. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Footrest
Courtesy of AUDI OF AMERICA, LLC
-- Pry off the cap -3- with a small screwdriver.
-- Remove the bolt -2- behind it.
-- Pull the footrest -1- downward -arrow- and remove it.