Absolutely not.
You would have to be an experienced mechanic and have specialty tools for the job. It will cost around $500-$600 for a gear swap.
If I were you, I would do a stall converter and gears at the same time.
A stall will make that auto come to life.
Be ready to spend around a grand on it though.
Congrats on the new mustang bro
Ok thanks for the info. My dad is a Mechanic i will see if he has the tools to do it
If so will save me some money.