Unfortunately, most of the time theists are not open minded enough for it to be even possible to deconvert them.

Ultimately, it all comes down to the individual. I've spoken to non-biblical believers mostly. Typically, their preachers and sunday school teachers have steered them away from the 'unsavory' parts of the bible. If I have a spare one, I loan it to them and then quiz them on what they learned the next time we meet. More often than not, they become non-religious but still 'spiritual'. 2 out of 5 become closet atheists. (No. That is not the unbelief of closets. lol.)
One girl recently became adamantly anti-old testament but said she still liked the 'pretty' parts of the new testament. I pointed her toward the misogynistic portions of the new testament and she slap got mad, like yelling mad. She asked her boyfriend if he knew that was what the bible said. He gave the wrong answer. lol. The worst part is that his dad is a well-known preacher.
If you show them the bad parts of the bible and they think about it on their own then that's all that we can do. There are some people that just can't be expected to think. Sometimes it just takes some time.

For the 'none, but spiritual' kind of people, I have found no method for making them look at the outside of the box. On my myspace page, I have three people like this. The more science the better it seems. However, the recent neurological article in another thread actually hurt the chances of a couple of them because now they know that all of the human brain isn't used. Their claim is that the rest of the unused portion of the brain is used for the 'life-energy'. It doesn't seem to matter to them that the human body doesn't produce enough energy to run the WHOLE brain. It's frustrating when reality holds so many undiscovered secrets. The DLPFC article was awesome. You'd think that being given information about studies concerning the brain would help. Physical science makes them think. Physical LAWS are impossible to refute.
A basic understanding of entomology, herpetology, astronomy, and epidemiology is a lot of fun when you tear apart the ten plagues. lol.

NOT TO STEREOTYPE. Women are surprised when you point out that the bible was meant to condition their responses to the world. Explaining Pavlovian theory concerning conditioned responses has become a conditioned response of my own. lol. Women DO NOT LIKE TO THINK THAT THEY ARE BEING 'CONTROLLED'. Barbie dolls are wonderful tools to explain typecasting of societal roles.

A preacher will never admit that he has 'changed sides' or even shifted a little. The ultimate hypocrites. They'll keep preaching the 'good news' until it stops paying the bills. Preacher's wives will beat their husbands with words of fear until the bills aren't paid and then make their husbands go to a better paying parish. So pretty much your run-of-the-mill candy ass hypocrites make the most devout preachers.

Moreso than changing just their ideology, I feel that it is important to replace their religion with more secular endeavors. Such as discussing politics and ethics. I'm bad about leading questions toward a single answer. MINE. lol.
I make them agree to leave god and the bible out of it. I excuse this by saying that I don't care what god has to say. I'm interested in what they have to say. god doesn't cast ballots. People do.

My spouse is a born-again-washed-clean-in-the-blood believer nowadays. Even she admits that the 'spirit' is in people, it's the god that gives it focus for her and her friends. My son is an atheist as of Aug. 2005. He said, "Dad, I just don't see how god could exist." He laughs at the ludicrous stuff in Revelations. He knows that there are no such things as dragons, gryphons and such. Santa Claus, the tooth fairy, and mr. easter bunny died and didn't get resurrected. lol.
My oldest daughter is in transition. She was baptized in 2005 but didn't 'feel' anything and has lost some interest. Her brother killed SClaus, TFairy, and EBunny for her. Right now, she's indifferent. I like that. By 10, I had been an atheist for six months.

Wow. This post went on and on.

When my new acquaintance Erica and her NEW girlfriend finish reading Ruth, we're going to get together and discuss lesbianism in the bible. Erica is an atheist but has never read the bible. I bought her one at the dollar store. I really want to get her to stop calling god a son-of-a-bitch especially in mixed company. lol.

I've always enjoyed:
www.skepticsannotatedbible.com
I f you click on the 'type' of biblical atrocity on the home page then it brings up a listing by book with chapter and verse and a brief leading statement. King James version.
Very handy if you don't remember exact chapter and verse.
HOWEVER, I would advise that you read and use your judgment on the verses around each instance. You'll find that biblical theists will cry 'Context' quicker than you have the verse read to them. lol.

I keep a dollar store bible in the van for the occasional person that wants to read it for themselves. I used to highlight verses but found that really irritated some religious people. So much so that the discussion was over before it began. lol.