Quote: "If you are the employer (even of just yourself) you can't opt out, the Workplace Pension changed all the rules.'"
Yes you can - and no it didn't; once the auto enrolment pension scheme has been set up and you're opted in - you can opt out by following the advice given by previous posters.
To the OP - I'd suggest that this kind of response is exactly why you should get your financial advice from a qualified independent FA, rather than a RL forum?