How to make the mouse left-handed in Mac OS X
This page explains step-by-step how to make the mouse left-handed in Mac OS X. Unless you have a single-button mouse, your mouse is set up for a right-handed person by default, with the primary button on the left. However, you can swap the function of the mouse buttons from the default left click, so that a right click is instead used for selection and dragging. You'll just need to remember to press the opposite button to what is called for when you are following instructions (for example, if you are requested to right-click on something).
Note: The following abbreviations for keys on the Mac are used: Ctrl is used for the Control key, Apple is used for the Command key, and Alt is used for the Option key. For keyboard access, make sure 'Full keyboard access' is turned on - you can turn it on or off by pressing Ctrl + F1 at any time.
Step 1: Open the 'Keyboard & Mouse' window
Make sure you are in 'Finder'. If necessary, press Apple + Tab to cycle through the open applications until you return to 'Finder'.
Click on the 'Apple' icon on the menu bar or press Ctrl + F2.
Click on 'System Preferences', as shown in Fig 1, or press the down arrow key to highlight it and then press Enter.
In the 'System Preferences' window (shown in Fig 2), click on the 'Keyboard & Mouse' icon, or press Tab repeatedly (you might need to press Ctrl + F7 first) to cycle through the icons until the 'Keyboard & Mouse' icon is highlighted and then press the Spacebar.
Step 2: Swap the primary and secondary mouse buttons
In the 'Keyboard & Mouse' window, make sure the 'Mouse' tab is selected. If it is not, click on it, or press Ctrl + F7 to highlight one of the tabs and then press the left or right arrow key to select it. Depending on the mouse you are using, you will see something like the window shown in Fig 3, which shows the default button settings for a right-handed person.
Click on the drop-down button to the right of the picture of the mouse and select 'Primary Button' from the list, or press Tab until the drop-down button is highlighted and then use the up and down arrow keys to scroll through the options.
Click on the drop-down button to the left of the picture of the mouse and select 'Secondary Button' from the list, or press Tab until the drop-down button is highlighted and then use the up and down arrow keys to scroll through the options.
(If you prefer to use your mouse as if it had a single button, select 'Primary Button' from the drop-down lists to both the right and the left of the picture of the mouse.)
You can also change the function of the side buttons and scroll ball (or scroll wheel), if your mouse has these.
When you are finished, click on the window's red close button or press Apple + W.