Do you just buy the connector prewired and splice them in?

Or do you somehow wire directly into the connector? If so, how?

 

Buy it prewired. Unless you have the crimping tool and the terminals.

 

If it's just the plastic shell on the factory connector that's broken, you can remove the pins from it and insert them into a replacement shell. If the wires or pins are damaged, you can cut the old connector off and crimp new pins on, or you can buy a new connector with pigtails attached and splice onto the factory wires.

 

If you get one with the pigtail from GM, all the wires will be white. I found that out with my digital EGR connector - 4 white wires, and I ended up mis wiring the valve. Parts guy told me it was because it can fit other applications, but I think it reduces manufacturing costs. I know it costs less (in this case by 75%) to use only one color.