4. Actually there is a drain plug on the steering unit it is accessed from the bottom, needs a 12mm socket. when it is off turn the steering wheel to either side slowly it will suddenly start draining leave the steering alone it will drian nicely takes about 10 mins. When it looks like it has completed, move the steering wheel a couple times from lock to lock, then put the drain plug back. It has a copper crush washer so you can use it more than once but try and replace it if you can. Then replace the filter in the pump unit and refill. During refill turn the wheel from lock to lock till the system releases all the air bubbles. Best to do this while the front is jacked up as it is easier to turn the steering wheel, just use the tire. This gives you a complete fluid flush for your PS.
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)