how do i change my name

When you prepare your tax return use the name that matches your current Social Security card---your name is entered in MY INFO.

And to update your TT account

https://ttlc.intuit.com/community/account-updates/help/how-do-i-update-my-turbotax-account-information/00/25927

You enter your name that is on your current Social Security card on your tax return in the My Info section of the program.