Module Activated that isn't used - want to remove

I am upgrading a client and I have run into the issue that somewhere along the way optional fields was activated in the company data.  But they have in fact never owned it so it must have been done with a 30 day trial license.  Now when I upgrade the data it wants me to install this module.  I have installed optional fields and I can now do the upgrade but I would like a reliable way to remove the existence of this ever being activated so future upgrades do not require this step.