Tell them you are trading in your 4-door sedan for a 2-door convertible.
Tell them you've become a football/NASCAR/baseball/soccer/golf addict and all of the best shows are on Sundays, all day. Your only hope is to go to an expensive psychiatrist - but you have no money because you also have a gambling addiction.
Tell them you have to go back to school (junior college or trade school, of course) to learn computer technology, Internet and website design. You have to go to class on Ministry School meeting nights and study and work on your computer on the weekends.
Tell them that you have piles (hemmorhoids) and can't sit through meetings any more because they've (both the piles and the meetings) become a "pain in the ass."
Tell them you can't go door to door because you have gout and Morton's neuroma (a very painful nerve mass in the foot), so the only "witnessing" you can do is on Facebook, Topix, and Yahoo!Answers.
Tell them you've recently realized that you've become one of the "anointed." Jehovah's "holy spirit" speaks to you directly since you've become a member of the "faithful and discreet slave" class. (Wait for their answer on this one: Will it be "only the Governing Body members are the FDS"?)
Grow a mustache or beard. Wear a pony-tail.
Start wearing plaid shirts with striped ties to meetings.
Wear mismatched suit pants and jackets with white socks and running shoes (the Morton's neuroma thingy acting up).
Come in five minutes late to every meeting, and then get up and leave five minutes early.
Hope one of my suggestions helps...
JV