How can I turn on/off Blackbook services?

Must be done under dealership Master (Administrator) account.

This is done in IVM under Settings -> Service Wizard -> click 'Book Values' tab to expand that section

The Blackbook box in that section will have a Cancel link. Click the link and a cancellation screen will come up.

A reason for the cancellation has to be selected from the drop-down box on the screen before the Save button is clicked. After Save is clicked, the screen will go back to the Service Wizard page. Click Save on this page to finalize the cancellation.