Step 1
Tap Manage Displays. Tap All Layouts Tap the Layout name. Tap the pencil icon.

Step 2
Select a text element. Tap the Font button. Select a new font. Tap Done.

Repeat as necessary, and then you may Save the studio file and/or publish it. Tap Save.

If you want to publish the changes, click Preview, then Publish. Make sure you keep the same studio file name.