The single heating element in the bread maker will not generate enough heat to roast coffee in a reasonable amount of time. I roasted for over an hour when I experimented with a single heating element and the beans only got a little toasty.
You can attach the second element the same way it was attached in the other bread maker. It should be attached to provide heat to the middle portion of the bread pan.
Drill the holes for the element connections first. Make sure you have a good fit.
Once you are satisfied with the fit you can attach the element to the unit using the brackets you saved from the other bread maker.
Now you’re ready to connect both elements. You should have already located the hot and neutral wires from the power cord. You can splice into any wire from the source before it goes to the motor. You don’t want to splice anywhere after the motor.
Use the heat shielded wires you gleaned from the disassemble. Those are the wires with the braided covers. It doesn’t matter which post you connect the neutral or hot wire to.
Plug in the roaster and the motor should turn with the heating elements emitting heat. At this point you have enough electronics in place to roast coffee.