Default Photo app change from "Gallery" to "Google Photos"

I have a ton of pictures that i've taken over the years. They are all accessible through google photos. When I take new photos they are automatically backed up to google photos. So, all is well there...

My problem is this. When I want to upload a photo to facebook, set a contact photo, or pretty much access a photo or video through any application it automatically opens "Gallery". Is there ANY way to change the default app to "Google Photos" or at least show the Google Photos in "Gallery"? It's driving me crazy!

Other than that, I'm loving my S6 Edge+!! :D