How do I stop an Object Event Handler from running?
August 2013 and newer releases
To stop an Object Event Handler from running you need to perform the following steps:
1.) Go to the Configuration->Site Configuration folder and open the Process Designer.
2.) Select the object that the event handler you wish to stop executing is associated with.
3.) Set the selectors for Create, Update, and Destroy to [No Value] for the event handler you wish to disable.
4.) Save the Process Designer workspace.
5.) Click the Deploy ribbon button.
It is always best to disable any object event handler before deploying any custom objects that the object event handlers are associated with. This will help prevent the event handler from arriving at an undefined state if there are errors due to missing fields or changes in the custom fields for the custom object in question. The event handler test harness should conform to best practices and the test step should always be performed again before reattaching the event handler to the redeployed object.
For further information on best practices, please see Answer ID 8392: SPM/Process Designer Best Practices.