The thing I found that works the best is to get your spouse to see the inaccuracies of the beliefs one at a time and then it will have less and less of a hold on them. Ask him to help refresh your memory on the beliefs by asking simple non judgmental questions and let him answer without judgement or argument. Let him see things for himself without having to be on the defensive.
Since it's the Memorial you could say:
You: I've forgotten a lot of the details of who eats of the bread and the wine, such as where the number 144,000 comes into play.
Him: There will be 144,000 who are chosen to rule with Christ in heaven Revelation 7:4. 12,000 from each of the twelve tribes of Israel.
You: Are they literally from the 12 tribes?
Him: No that's symbolic
You: Ok so they're not literally from the tribes of Israel but does that mean that the number 144,000 is symbolic too?
Him: No, that's literal
You: So one part of the scripture is literal and another part is symbolic? How do we know that for sure?
Him: That's what the faithful and discrete salve says is the understanding.
You: Are some of the 144,000 who partake of the bread and wine at the memorial, women?
You: So the women who partake of the emblems don't teach or have any position in the Congregation now, but they'll be ruling with Christ in heaven and judging mankind.
You: Yeah....ok...it's convoluted but it's starting to come back to me....I guess I was never sure about how I could prove anything like that to anyone who wasn't already a JW.