How to hack a USB keyboard or any keyboard for that matter. Send inputs into the computer without a pesky microcontroller.
Step 1: Open up the keyboard
Open up the case. You can use a screwdriver or an any ridiculous looking multi-purpose tool. Sometimes even after all the screws are removed the keyboard still won't open up. In this situation, don't worry, just forcefully pry the case apart with your screwdriver. It doesn't matter if you break the case. You don't really need it.