Macintosh OS X to 10.3
These instructions should work for all versions of OS X up to 10.3.
Step 1: Click on the APPLE icon on upper left corner of screen and single click on SYSTEM PREFERENCES...
Step 2: Single click on INTERNATIONAL.
Step 3: Single click on KEYBOARD MENU.
Step 4: Single click on the languages you would like to install then close the window (click on the X on upper left hand corner of the window).
Step 5: Click on the U.S. Flag on the menu bar on the top of the screen. Choose language from the list.