After you create an association for an issue operation, Jira prevents you from creating another association for the same issue operation by removing it from the list of available options. In order to change the association to a different screen, you need to edit the existing association, as follows:

1. Browse to the Configure Screen Scheme page for the screen scheme to be configured.
2. Click on the Edit link for the association you wish to edit. This will take you to the Edit Screen Scheme Item page.
3. Select a new screen to associate with the issue operation.
4. Click on the Update button to apply the change.

If you decide that one or more existing associations are no longer needed, then you can delete them from the screen scheme by performing the following steps:

1. Browse to the Configure Screen Scheme page for the screen scheme to be configured
2. Click on the Delete link for the association you wish to delete

Please note that unlike other similar operations, deleting an issue operation association does not prompt you with a confirmation page. As soon as you click on the Delete link, your association will be deleted immediately.