To insert or delete masters, you can click buttons on the Slide Master View toolbar, choose commands from the Edit and Insert menus, or right-click a master in the thumbnails on the left of the slide master view.
To delete a master:
- Click the Delete Master button on the Slide Master View toolbar.
- Choose Edit → Delete Master.
- Right-click a master thumbnail and choose Delete Master.
- Click a master thumbnail and press Delete.