How can people be actually converted?

Have you ever con­vinced a re­li­gious per­son to be­come athe­is­tic? How did you do this? How long did it take? Were the peo­ple in some sort of life crisis, or were they just liv­ing along?

This is prob­a­bly a quite difficult task of per­sua­sion. So sto­ries how peo­ple were suc­cess­ful at it could be very in­ter­est­ing to im­prove ones’ per­sua­sion abil­ities.

Re­lat­edly, it might be in­ter­est­ing to know what re­li­gious groups have gath­ered on tech­niques to con­vert peo­ple to their re­li­gion—are there some man­u­als/​tech­niques float­ing around?