WARNING: This page is about a different car, the 2009 Audi TT and 2008 Audi TT. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Tools To Remove Reverse Gear Synchro-Hub
Courtesy of AUDI OF AMERICA, LLC
-- Before pressing off, remove circlip.
A - Separating device 22 to 115 mm, for example Kukko 17/2