From the help menu
Customize shortcut key assignments
You can assign a shortcut key to a command, macro, font, AutoText entry, style, or a commonly used symbol.
1. On the Tools menu, point to Customize, and then click Customize Keyboard.
2. In the Categories list, click the category that contains the command or other item.
3. In the File list, click the name of the command or other item.
Any shortcut keys currently assigned to the selected command appear in the Current keys bo4. Do one of the following:
• To add or change a shortcut key assignment, click the Press new shortcut key box, press a shortcut key combination that includes a modifier key, such as SHIFT, CONTROL, OPTION, or z, and then click Add.
• To remove a shortcut key, in the Current keys box, click the shortcut key you want to remove, and then click RemovNotes
• After you press the key combination you want to use as a shortcut, the Currently assigned to box appears and displays any other action assigned to that key combination. If the key combination is already assigned to an action, and you click Add, the previous action assigned to that key combination will be lost.
• You cannot remove pre-assigned shortcut keys. You can only remove shortcut keys that you've assigned.
• To restore all shortcut key assignments to their original settings, click Reset All.