So far I am off to a good start. I have salvaged all the power supply, motors, drivers, belts, pulleys, and metal I will need. I still need to find some optoisolators to go in between the computer and the driver IC. 

I don't want to make any permanent modifications to my mill. That way I can still use it to make parts. So my first step is to begin machining a new part that holds the toothed pulleys onto the shaft of the lead screws.