This article is from the Ducatis Motorcycles FAQ, by Duke Robillard duke@io.com with numerous contributions by others.
Basically, you drive it out from the WHEEL side of the caliper using a
punch. It has a spring collett on the outer end that fits into a recess on
the caliper. Looks kinda like this:
/ \ ===| |============= < drive it out from the INSIDE ===| |============= \ / PIN COLLETT
 
Continue to: