The documentation on this is not all that clear. You do it this way (but can use thinner 18 awg wires). Alternately you can cut the connector on the low voltage side of the power supply and connect directly to the motherboard.
Note + needs to go to 2 inputs on the motherboard and - also to 2 inputs.
More discussion in my build thread when I ran into this and other forum members provided helpful comments.
I also ran into the z rod too long issue and yes you cut it off if you want to use the full z axis range the machine can support without crashing into the table. I used a hack saw to shorten mine.
Here’s how mine looks.