There sometimes isn't any way to revoke your membership without risking some tension with family (depending on the local congregation and family concerned).
Disfellowshipping, by current Watchtower rules, involves far more than "some tension". Some tension is a huge understatement.
There may be a few exceptions. But in my case 41 years ago in 1977 when I proudly took my stand, made my exit, my two boys decided to remain with their mother. Not a problem -- then. We continued for a few years to spend precious father/son time together, nothing spiritual, of course. Go to the beach, take certain trips, discuss school problems, etc.
Early 1980s the society changed their rules. Had I known about those new rules, which then prohibited family association, I'd have probably taken a different route to exit when I did in 1977, now known as fading. Four years too late.
The disfellowshipping has never been the problem which, in turn, separates families. It's the punitive measure that goes along with it. The remaining family members are held hostage with the threat of being disfellowshipped themselves -- or keep their forbidden relationships secret, always looking over their shoulders for fear of reprisal.