[Leica] Dust in viewfinder

["Simon Cheong" <qecl@hotmail.com>]

Hello all,

I recently notice a speck of dust on the focusing patch when I look through
the viewfinder of my M4.  The size of the dust is about half the length of
the focusing patch and is affecting my focusing.  I can see the piece of
dust clearly from the smaller rangefinder window and I am sure it is on the
small mirror within the rangefinder system.  Could anyone on the list tell
me how to remove dust from the rangefinder system without taking apart the
camera?

Thanks
Simon Cheong