The stock Mad Catz Wire Harness is not all cool with Sanwa JLF because it does not connect well.
There is no guide to replace the Wire Harness.
But I just told a guy before to splice new into old, and it worked super for him.
Stock Mad Catz Wire Harness has white connector on both ends.
You can solder new Wire Harness directly to Mad Catz PCB after removing connector if you want.
But you mention you not solder before.
So you can just add Quick Disconnect to end of new Wire Harness, and cut Mad Catz Wire Harness and crimp on respective Quick Disconnect for that.
Or use Butt Connectors, or Terminal Strip, whatever you want.