Computer

A simple attempt is to just disconnect the battery for 10-15 minutes. This will reset all parameters to original. If you have a check engine light on, this may turn it off. However after the car runs for a while the OBD computer may sense the error that caused the Light to come on and it will come back on.

You may regret disconnecting the battery! If you are having problems you should take it to your dealer as your car should be under warranty.

You can't, it needs to be reset at the dealership

Don't disconnect the battery. Take the vehicle to a local auto parts store and get the trouble codes read for free if a check engine light is lit. You didn't tell us the reason that you want to reset the computer.