I have an existing HID headlight that has a crack on the back of the plastic assembly. Can I replace it with a non-HID headlight and just swap the bulbs, ballast, etc? Technically, this is how people who have stock halogen upgrade to HID, right?

 

yea you should be fine if im reading your post correctly. I had non-HIDs when I bought my car, added the starter, ballast and bulbs and was ready to go, 10k miles later no problems.

 

If you have the factory HIDs, the bulbs might not mount the same. Check the location and size of the mounting pins (not the electrical pins) on your HID bulb and compare them to the pins on the halogen bulb.