How can I disable the macbook keyboard with Shift key held down on a password protected macbook? This question is a bit strange, but here's the scenario:


macbook air laptop with El Capitan Mac OS X
currently logged off any account
liquid damage on keyboard has caused shift key to be permanently pressed
password to admin account has some lowercase letters and numbers
restarting enters "safe mode" 


The machine has no sensitive data, so I'm happy for a solution even if it wipes out the admin account. I'm also happy to buy a USB keyboard/plug into an external screen if that will help.

How can I disable this pesky shift key? Or disable the built in keyboard all together?
Disable keyboard:

sudo kextunload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/


Enable keyboard:

sudo kextload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/


For manipulation, you can use the virtual keyboard:
System Preferences > Keyboard > Keyboard > Display panel "Keyboard" and "Symbols" in the menu bar