The sensors arent too bad to change... the hardest part is usually the rotors have to be taken off... but being they were just replaced, they should be pretty easy to remove.

The wire for the sensor has a metal channel that it is encased in, the channel is bolted to the suspension arms... and then makes a connection down the line a little. The sensors are over $100 a piece... so you're going to want to diagnose that light, and first be sure its a sensor... and second, know which one. There is a site I recomend to anyone with CEL or ABS lights, follow this link and click on "rescources", then follow his easy directions and check the code with his cross-reference. It is for the CL, but everything is the same.

Hope that helps out... and hopefully its just a sensor... as they are the cheapest parts in the ABS system.