Select the monitor you want to reposition in this case it will be monitor 2 left of monitor 1 or in front of monitor 1. This will allow your mouse to cross the middle of the screen.
After repositioning your monitors click Apply. The Main display is the dark blue gray monitor. The next step will demonstrate how to select monitor 2 as the Main monitor.
After rearranging your monitors the primary display will need to be set. The primary display is the monitor that has the notifications and time in the lower right. This is dependant on the position of your start menu location as well.
After that your cursor should move about the middle of the screens and the Start button should be on the screen of your choosing.