Copy this file to the directory '/usr/lib/kbd/keymaps/mac' and configure your startup scripts to use it.
Copy this file to a file called '/usr/X11R6/lib/X11/xkb/symbols/es' and add the following entry to your XF86Config:
Section "InputDevice" Identifier "Keyboard0" Driver "keyboard" Option "XkbModel" "macintosh" Option "XkbLayout" "imac-es" EndSection