Changing the default launcher in Android N is done differently than in Marshmallow:

 - Go into the Settings app.
 - Go to Apps
 - Press the settings gear in the top-right (not the triple-dot).
 - Scroll down to "Home app." By going into the home app section, you'll be able to change your default launcher.

Alternatively, you can just search inside the settings app for "Home."

**source:** https://www.youtube.com/watch?v=HpXBDnSIeiM