Change the brakes and rotors now ABS light is on?

Front or rear brakes? Chances are one of the ABS wheel speed sensors got unplugged, I would go back over your work to see if you can find the sensor that is unplugged or if the wiring got messed up. If you cannot find anything wrong, then we need to scan the system for codes which this guide can help you with.

https://www.2carpros.com/articles/anti-lock-system-testing-and-repair-abs

Here are the locations of the ABS traction control wheel speed sensors you can check it out. Check out the images (below). Please let us know what happens.

anything?