How to set all text in all slides to the same font?

I'm making a presentation that's looking a lot like the Frankenstein monster right now. There are 4 different fonts being used throughout all the slides, and I'd like to normalize this. I want to set all the text to the same font.
How can I do that?

I tried simply selecting all slides, but then you can't select the Font menu (and that's as far as my PowerPoint experience goes).


Select all the slides (Ctrl+A) using the Outline view. You can then change the Font for the selected text.


In 2010 and 2013 its very simple

1) Home Tab > Replace (click More arrow) > Replace fonts