You can customize how your mouse buttons function using the Logitech Control Center (LCC) mouse and keyboard software for Mac.

NOTE: If you don't already have LCC installed, you can download it. See answer 360023357693 for instructions.

To change the task a mouse button performs:

1. Launch the Logitech Control Center

   Apple Menu > System Preferences > Other > Logitech Control Center

   

2. In the Logitech Control Center window, double click the picture of the mouse you want to customize.

   

3. On the top-left side of the window, click Buttons.

   

4. Select the mouse button you want to configure, and then choose the action you want it to perform from the Assigned action drop-down menu.

5. In the Details box, choose the task you want to assign to the button.

6. When you're done customizing your mouse, close the window and return to the LCC devices window.

7. In the LCC devices window, you can either select another device to program or close the Logitech Control Center to exit.