There are four ways to leave the 'Truth'...... alive............you can be Disfellowshiped...... then shunned, you can formally Disassociate yourself and be shunned........ you can Fade. The first two words belong to the Society, Fade on the other hand is defined as 'to gradually grow faint and disappear.' 'Walking away' has it's own negative connotation about one's commitments and relationships.
I think some folks feel uncomfortable with these words. Perhaps none of them describe what you want or feel.
How about........Disengage?
It is an interesting word that means ' to separate or release (someone or something) to which they are attached or connected.'
There is another definition as used in Fencing. 'To pass the point of one's sword over or under the opponent's sword to change the line of attack'......... Theocratic warfare anyone?
For those seeking to separate from the JW'S......... disengaging may be the more accurate word to describe you to yourself. A word that you can use....... not one that they use. A big part of leaving is to not define yourself by their words.......nor playing by their rules.