there is a contrib "sme-server-update-system-1.0-1.noarch.rpm", that panel can update contribs.
in the "advanced options" there is the chance to delete contribs.
if the "delete" is not visible in your system, enter this command in the console:
"/sbin/e-smith/db configuration setprop updatesystem RemoveRpm enabled" (it is one line)
cheers