Lease Buyout in TX...How to Transfer Title?

I just bought out my X3 lease from BMW FS. Received the title in the mail and got an appraisal from Carmax, only to find out I have to wait 30 days before they can buy the car from me. I’m not clear as to where I need to go to complete the title transfer into my name. Is it the DMV or the Tax office?

Dmw office does all that