WARNING: This page is about a different car, the 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Driving Roll Pin Into Input Shaft
Courtesy of VOLKSWAGEN UNITED STATES, INC.
Guide a 9 mm diameter drift -A- into oil drilling and drive spring sleeve -B- in until it touches drift.