You cannot turn this:
with a mere minor retool. Forgetting about the difference in the shoulders, the chest transforms radically differently, the waist is fundamentally different and the feet/legs transformation is fundamentally different.
Two minor mold changes separate Prowl and Jazz. In both cases the head is attached to the roof/front windshield of the car mode and folds down to reveal the head. The chest in both cases is the front of the vehicle from the doors forward folded at a 90 degree angle. In both cases the feet are formed by pulling the rear of the vehicle- from behind the doors back- down and apart. You can turn Jazz into Prowl by:
1. Adding a hip rotation allowing the waist to turn around 180 degrees so that the rear of the car forms the front of the feet and legs; and
2. Turning the wheels/shoulders on Jazz so that they match the angle of Prowl's.
Structurally, as robot modes they are virtually identical. You can keep the robot portion- the infrastructure engineering, so to speak- the same and simply change the exterior to change one to another. Not quite a "repaint", but much less than a new mold altogether, saving wads of money on engineering and time to produce. The infrastructure can remain the same and only the exterior need change. This is why I say Jazz will come from this basic mold. I have both Jazz and Prowl's G1 figures. They really are not that different.