unfortunately, you can not, Westinghouse uses what is referred as the "Muse Platform" is is one of several operating systems for "Smart TV's" And, with this system you only get about a half dozen of so "imbedded apps." These are apps that come preloaded from the factory. This system does not have a web browser, i.e. I.E. and/or Google Crome, and does not have the ability to download any additional apps or a web browser.
I know this really sucks, I too, found out the hard way, by purchasing several different "operating systems", There are about a half dozen or so such platforms, i.e. Google TV, Muse, Yahoo, and Roku to name a few.