no need to change your grip. federer hits eastern and has, by some measurements, the 2nd highest topspin on tour.
just hit with a more closed racquet face at contact. think 10-15 degrees. you might find that you have to swing forward faster, or adjust your stroke otherwise, but it will come through feel. hitting with a closed racquet face at impact gives you more topspin than hitting flat.
much easier than messing around with overly wristy movements.
Disclaimer: I'm NOT a coach...
Real tennis: https://www.youtube.com/watch?v=yDqnkLJ9BtM