Well I took a three tier approch to it. For the family I most cared about, well they got the face to face talk. Boy Telling my kids was tough, but they took it far better then I had hoped. For the family that was somewhat less important, well they got a detailed letter. The last group, IE. the ones that I felt would not handle it well got an email. That last group included my southern baptist aunts back in georgia. Oddly enough no one ran away. OH I have a few relatives who worry for my soul, but no major hatred and I still maintain contact. So your mileage may be a bit different.
Best of luck to you
Beni