HI MY outback Legacy H6 AWD auto has the VDC light on, and an engine symbol. I have tried to turn this off using the VDC switch but it does not work. Is this a big job?

Any time there is an issue with the performance of the engine or trans, the VDC shuts down since it uses the engine and trans to operate in conjunction with the ABS. You will have to go to an Autozone, Pep Boys, or other equivalent store and have your error codes read. Once you get the code, post it back here and someone will look up the meaning. Once you replace the faulty part, all lights should go out.