I have a large roughly 40x20 Lazy Ell shaped pool. I only have one light on the wall at the deep end of the pool. I am replacing the existing light and housing which burnt out a year ago. If I swap it out with an incandescent light can I easily upgrade to an LED light in the future by just swapping out the bulb? Or do I need to change the wiring and housing and/or drain pool below light level to switch to LED?