One thing that really helped me was to see the Dateline expose. Here was information from a well-recognized source that pointed out how much like white washed graves this religion was. If we get an opportunity to see more on broadcast TV (some of us don't have cable or satellite) let your loved ones know in a subtle way to watch the program.
Clip articles from newspapers or magazines and leave them lying about. If they visit you they will see for themselves.
If we 'preach' to them they'll turn off as they've been taught to avoid apostates. Finding out the truth from news sources is a powerful inducement to examine the teachings they espouse.