Is sex change possible?

Yes: Sex change is possible in these modern times with advanced medical techniques. The techniques have been refined over the last many years.

Yes : It is a long and careful process usually done by a team.

Sex: reassignment surgery is possible.

Depends/define ?: You are what you are. Your sex is not determined by a doctor at birth, it is based on what your chromosomes are & how they build out your body parts. With modern surgical/ medical techniques you can change the outward appearance, but you can't change your chromosomes. They will remain the same whatever persona you decide to adopt.