There should be an uninstaller application in your Utilities folder (/Applications/Utilities/) called either IntelliPoint UnInstaller.app
or IntelliType UnInstaller.app
If those are not available, the extensions are saved in /System/Library/Extensions
- namely MicrosoftMouse.kext
and MicrosoftKeyboard.kext
. In order to safely remove these you will want to run the commands:
sudo kextunload /System/Library/Extensions/MicrosoftMouse.kext
sudo kextunload /System/Library/Extenstions/MicrosoftKeyboard.kext
before dragging the files to your trash. If you don't it may not allow you to delete them until you restart.
Lastly, under /Library/Keyboard Layouts
there may be a file called Microsoft Keyboards.bundle
you can drag to the trash and delete as well.
kextunload
stands for kernel extension unload.
Credit to Suspicious Package for the details on the installer.