This might help

https://www.ti.com/lit/ds/symlink/sn54ls73a.pdf?&ts=1589740367175

and this

http://www.ti.com/lit/sl/scyd013b/scyd013b.pdf?&ts=1589740470875

 

If I were changing your TFF circuit to JKFFs, I would reverse engineer the circuit to come up with the state diagram for the TFF realization. Then, using that state diagram, design the circuit with JKFFs. I won't tell you how to do it because it is Homework Help. In other words, go backwards to the state diagram for the TFF circuit and forward with the JKFF design. There is a way to "cheat" (IMHO) by hooking up a JKFF to act like a TFF. However, you won't learn anything.