Windshield Wiper

["Ben Prince" <blprince2@comcast.net>]

On my BN1, the left windshield wiper blade only travels a few degrees back and
forth.  The arm slips on the shaft that extends from the wheelbox (items 40
and 35 on page 94 of my year-old Moss catalog).   How does one remove the
wiper arm from the shaft?  Is there some type of catch that must be released?
I gingerly pried without success, but I'm afraid increased force will break
something.  After the wiper arm is off,  what is the best way to correct the
slipping?

Many thanks,
Ben