Its really difficult but you should at least try and spring your wife out as well. No point in being left wondering 'what if..' later on. Having said that it sounds like that attempt should leave you with a fallback position with plausible deniablity
You could go cold turkey and explain your conscience doesnt allow you to continue. "I have made an informed choice not to attend for now, and if that changes I will let you know" repeat until blue in the face, particulary if your wife defies your wishes and drags some elders in.
If pushed you could explain to your wife only - no one else - that there are issues that defy facts (the flood for one - http://corior.blogspot.com/2006/02/part-1-general-description-of-flood.html), that defy a normal interpretation of Christian Doctrine (the Mediator - http://www.jwfacts.com/watchtower/mediator.php) and that defy moral behaviour (child abuse policy - http://www.jwfacts.com/watchtower/paedophilia.php) - combining these 3 EXAMPLES makes it impossible for it to be the right religion, if such a thing exists.
All the other advice is great - be the best husband and father you can be, try and arrange fun stuff that conflict with meetings and service, cultivate a few mutual friends outside the KH.
PM me if you like :-)
