Keyboards don't have much in the way of active electronics anymore. They are mainly a matrix of switches.
The keyboard can be removed and cleaned with alcohol, or un-plugged from the mainboard.
They are usually in layers, a pressed key connects one layer to another at a specific position to cause the computer to interpret what key has been pressed. A spilled soda will stick contacts together but is not likely to fry anything in the keyboard.
Give make, model and I'll see I can find dis-assembly instructions for your machine.
If you really want to disable the keyboard, do this:
Start>Run>Services.msc>Shell Hardware Detection Service>Disable
You will also lose autorun for the CD/DVD drives.
Now with this service disabled, uninstall the keyboard again and it will stay gone.