I ended up getting someone to do it. It was expensive, and I think I could have bought the unit online and done it myself. But water, electricity and my lack of knowledge doesn't seem like a good combination.
The light was also causing my panel to short out, so I had to run the pool pump manually. The repair guy showed me that I could have just disconnected the light and solved the problem. But I'm comfortable with most pool stuff, but not so much with the electricals!