Choose Slide - Slide Properties

Choose Slide - Slide Properties and then click the Page tab

Choose Slide - Slide Properties and then click the Background tab

Choose Slide - Layout

Choose Slide - Change Slide Master

Choose Slide - Change Slide Master - Load

Choose Slide - New Slide

འདི་གུ་ གསལ་སྟོན་ ཕྲ་རིང་ ཨེབ་གཏང་།