1.View master page design
Use View->Slide Thumbnails to open Thumbnails. You will find all the slide Thumbnails in this dock window.
2.Switch to Master page design
Use View->Master->Slide Master View to switch, or, for shot, on the left bottom of the slide view, there is a button to switch to master view, you can click it to switch quickly(you can also use this button to switch back to normal slide view)
3.Create, Delete, Modify the master page
In the thumbnails, you can create, delete or modify the master page. And also change the format of the title, subtitle, or placeholder, like the font properties, paragraph properties, numbering&bullet properties, etc.
4. Apply the master page
1)Change back to the normal slide use View->Normal, select the slide you want to change the master page format.
2)Open the Slide Templates in the property sidebar, You will see all the master page will appear under the "Used in this presentation" tag.
3)Select the master page you want to apply to apply the master page templates.