1. Navigate to the Quick Settings Bar in the lower right of the desktop. It may also be on either side of the desktop, but will always contain the time, audio control, and WiFi and battery levels.
   
   
   
   
2. Select WiFi, it is generally the top bar with the WiFi logo on the left hand side and the name of the network you are connected to on the right.
   
   
   
   
3. Select the WiFi Name which you would like to disconnect from, in this instance it is UWMWiFi.
   
   
   
   
4. Select Disconnect next to the Close button on the lower portion of the prompt that appears.
   
   

More information and help can be found on Google's official help page.