For me I had to do research and bible study. I know that is a pain in the ass, but once it becomes important enough to you to KNOW the TRUTH, then you likely won't be able to help it and will do the research like you have never done it before.
Just reading the bible on it's own in context is usually enough to convince many the JWs are wrong and that the bible doesn't actually support many teachings we believed as fact. Just reading the bible left me with a very sour taste in my mouth about the God of the OT compared to the Christ of the NT and reconciling the two.
Then there's doctrinal issues like 607 bce. This for me was the crux of the whole thing as if 607 is wrong then so is 1914, 1919, the FDS, the GB, this generation etc etc all hangs off it. I can tell you it is wrong but to prove it for yourself makes all the difference. The Gentile Times Reconsidered demolished 607 for me.
Also once you understand that this is a mind control cult then you can see through the subterfuge easily.
So you are going to have to read. Lots. But it is worth it, because by proving to yourself it is bollocks then your mind can be free(r) of the guilt and fear. It won't completely go, but it is a great help.