Trading mistakes

I bought a Variable annuity for a client a few years ago. Both he and I were under the impression that there was a living benefit rider on it. (the one where you can withdraw 5% per year of the "income base") However, I looked and I never put a rider on it. There is no rider attached. He bought it three years ago, so there is still about a $ 5000 withdrawal penalty ( I was thinknig of 1035ing to another with a rider or even one with an upfront bonus to take out his penalty) I have not told him yet but am planning to. Ideas on a good way to handle this? Thanks.