I completely changed my name a year (or so) ago... first name, middle names and surname to boot!
I wanted to send a very clear message to MYSELF and everyone from my FOO (those in the know - who knows? who cares?), that I am no longer a part of their family.
It was one of the most liberating experiences I've ever had and although there were a few people who had issues with my name change ("that's a bit weird, isn't it?") I kept reminding myself that this is MY life and I am in charge of living it. I am NC with my FOO and have been for over 2 years and my life has gone from strength to strength as a result.
My name change was the final thing to "change" and now I just work on my "stuff" as it arises... I'm free to be me.