I had a very hard time reading Ray's book as well, and I feel that most of it was not beneficial to me, as I had already decided that the organization was evil.
Just to include an answer to the OP:
The Watchtower publications actually tell them to get out of the organization, using quotes from those same publications. There are books that help you show them this. The first is Who is the Faithful and wise Servant by Duane Magnani. It has quotes like "Putting forth the effort to locate that older publication and then studying the pages referred to." WT 6/15/85, p. 12. "It is obvious that the God of truth will not look with favor on persons who cling to organizations that teach falsehoood. Would you really want to be associated with a religious organization that had not been honest with you?" Is this life all there is? 1974, p. 46 "Is religious history of any benefit?" "This information has helped many people identify Christs true followers today." WT 9/15/87 p. 30 You can imagine the types of quotes found in that history. Combine this with How to Rescue your Loved One from the Watchtower which shows how they have changed doctrines back and forth and condemned those who didn't change with them, and really exposes them as men making guesses rather than having God's Spirit, even exposing them for the bloodguilt of condemning medical procedures that were later allowed, all with quotes from the publications made available through the organization itself.
May God be with all of you in this endeavor,
SOG