WARNING: This page is about a different car, the 2004 Volkswagen R32. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Removing Seal For Input Shaft
Courtesy of VOLKSWAGEN UNITED STATES, INC.
Carefully remove seal using screwdriver.
When transmission is disassembled seal can only be removed using sleeve 30 - 21.