gunked up keyboard suggestions?

[Paul Rubin <phr@netcom.com>]

My 755cx keyboard has gotten gunked up from years of use.
Lots (maybe most) of the keys are stiff now, slowing down my
typing.  Anyone got a good way to clean them enough to make
the typing action lighter?  I think more likely I just have to
replace the keyboard.  Anyone know of a good vendor for
this kind of thing, and is the replacement operation difficult?
It's not totally obvious from looking, how to remove the old one.
Thanks.