Lexmark CX860
Turn off the printer.
Open door C.
Remove the paper bail.
Remove the paper transport and staple finisher connector covers.
Unpack the staple finisher.
Insert the staple finisher until it clicks into place.
Close door C.
Turn on the printer.
Add this option to your printer to enable unattended printing, including automatic offset stacking and hole punching.
Continue to enjoy automatic stapling of documents as you print, copy, or scan. Change the staple cartridge when you are prompted to.