Do read this useful article first :

As I said in my Passle post of 3rd September - - the law impacts on every aspect of life; changing what you do within the legal profession is a very viable option.

I worked with a lawyer at a Magic Circle firm who really wanted to work in the music industry and found a way to switch from banking law to music law at a smaller firm. I also once came across a lawyer who was such a huge dog lover he'd become successful sole practitioner advising dog owners whose dogs had bitten people and who were facing possible orders to destroy their adored pets. Anything is possible!