Place all the society's book publications you can get your hands on from bygone decades on a table top.
Russell's Divine Plan of the Ages, Rutherford's colorful screeds, the books from the 40's--70's (mostly by Fred Franz) and
place a sign next to them and photograph the whole collection.
The sign might read something like:
Jehovah gave us these TRUTHS which are no longer True.......WHY?
Is the problem with Jehovah or somebody else?
Go to P.I.P. and have about 25 of these made into post cards and mail them anonymously to all the JW's you know.
Wait for the explosion!!