You can swap your left and right mouse buttons using Logitech Options. Here's how:

1. Open Logitech Options: 
   Windows: Start button  > All Programs > Logitech  > Logitech Options 
   Mac: Macintosh HD  > Applications > Logitech Options
2. Select your MX mouse. 
3. On the Mouse tab, in the lower left corner, check Swap left/right buttons.

   

   The curved arrow on the mouse in the Logitech Options interface shows that the buttons have been swapped.