The philosophy behind The Twelve Steps

What I wonder about the 12 steps, and having seen the bullshit episode with P&T, is why haven't the 12 steps ever changed?It is a big sign of the woo that someone somehow trips over these 12 steps, and now many years after they are still using the same unedited 12 steps.How do they know they are all necessary? Why not cut out one or two of them? Are they more or less effective if you remove the word god? etc. etc.What epistemic principle do they rely upon?/Soren