Mercedes: Heater Blower 1989 300E, occasional mouse, heater blower

Question
I want to get to the heater blower on my 1989 300E. I have the Model 124 service manual on CD-ROM, which describes removing the wiper and then the blower's cover, but although saying that the perforated plastic grille must first be removed gives no clue how to do this. I don't want to risk breaking the plastic, so have you any advice?

The fault is that for the last few days when the car is started the blower either runs or does not as the mood takes it, whether the car is warm or cold. I have examined the dedicated strip fuse and the small ones; all seem o.k. For some months the blower has given an occasional mouse-like cheep, so I suspect worn bearings or brushes. Of course, I should have checked it when the weather was good as it is now winter here in Toronto and I really need a dependable blower. Also I am working outdoors as another project occupies my garage. Have read the correspondence and links on heaters after finding this site two days ago and am very impressed.  Thanks in anticipation. Mike.  

Answer
My strongest advice:
Try to access a warm work area, for the sake of the plastic.

For answers, read this thread, and all links in it.

W124 Blower Motor Removal Photos
http://www.mercedesshop.com/shopforum/showthread.php3?p=321966#post321966

Have a great day.