Instructions
Download and install a shortcut key configuration generator, such as Warkeys or DotaKeys, or use a Web-based service, such as DOTA Customkey Generator. These programs and services will generate a file called "customkey.txt" that "Warcraft III" uses to enable user-modified shortcuts.
Click each icon representing a skill or item slot and select a letter or other key to use as a shortcut. The process is essentially the same for each tool.
Save your customized key layout to generate a "customkeys.txt" file. Place this file in your "Warcraft III" main directory.
Open "Warcraft III" and select the "Options" menu. Check the box next to "Custom Keyboard Shortcuts" and save your changes.