See if these links might help you. They don't have a YouTube video like you are looking for, but describe the set up process, which may help.
How does a pneumatic or hydraulic piston work? Pressure is applied to a piston that results in a force. P=F/A. If you're feeling really geeky, you can model pressure on the piston face instead of applying force.
Always be sure to couple at least a small damper to a piston force. Solvers hate undampened motion.