You can use options within the Design Tool to detach event handlers from Host Integrator components. If you also want to remove associated files, additional steps are required.
Detaching an event handler
Removing an event handler file
Before you delete an event handler, check whether any other component is using it. You can review components that may be still be using the event handler from the Type tab on the Attach Event Handler dialog box.
If you delete the .java file when an event handler is still attached to a component, the event handler will be displayed in red in the Attach Event Handlers dialog box, and you will be warned when you try to save the model that it cannot be deployed in its current state.