One by one, I am revealing to my LDS friends that I am now a Christian. I told another one yesterday. There was no drama. I'm not certain she even flinched, at least not outwardly. We discussed some key differences between Christianity and Mormonism, such as being saved by grace or saved by grace and works. It was a civil discussion, just as I'd expect from my well-educated and kind friend.
What is breaking my heart since then is that she said she is totally content with her beliefs and content to let others believe as they want. Key word: content. Synonym: at ease, comfortable, complacent.
God gets to us when we are not content. My eyes were wedged open because of the controversy over marriage equality. When I watched the Youtube video conversion stories of the members of the Adams Road band, one pointed out that he read the Bible as a missionary to prove a Christian minister wrong and then saw the doctrinal conflicts with LDS scriptures. Another friend of mine was offended by cultural differences between the members from his home state and the ones in Utah. Each person that left Mormonism can probably tell you what took them out of the drone zone, made them consider what they'd always accepted as being unacceptable.
If you are waiting to help a Mormon open their eyes, don't be afraid if they have a trial. Get ready to support them. It could be the magic bullet to wound them with the truth so they can heal in God's grace and love.