Here are the relevant sections. Which part are you talking about? There is a small plastic slider (#31) that is for reducing friction. There is a spring that rests against it that is for the gear shaft engagement button so that the button pop's up again as you take your finger off of it. So this is a minor issue to sort out. Your major issue is the main problem.
You've got cables that wear out along with bearings for the cable attachment and that switch that mounts to the transmission... is expensive if that is the issue. You may get lucky in that this is a lube, adjustment or wear on a cable issue that is affecting the proper engagement of the micro switches. A good independent familiar with Porsche 996's should be able to sort this out for you. The light on the dash is caused by the TCU warning you that the switch positions are not engaged. Some people report not being able to start a Tip S 996 if these switches fail in the wrong position. If you can get this car into D and safely drive it without the mode changing on you - I would head off to a service center ASAP. If it slips into N or any other position on it's own - flatbed it - don't risk it. Hope this helps.
