Sometimes, you’ll want to apply a new template to an existing presentation to change its design fast and easy.

1. First, open the presentation whose design you want to use. On the File tab, click Save As. In the dialog box that opens, from the Save as type list, choose PowerPoint Template. Then select Save.
2. Now, open your existing presentation.
3. In the Design tab, expand the Themes gallery and click the Browse for Themes option at the bottom. Navigate to wherever the template is located, select it and click the Apply button.

All your slides will adopt the new look and formatting prescribed by the template.