My ABS warning light comes on when I start the car. I assume its the relay. Is there another relay I can use to test if that's the case? Do I need to to unhook the battery before I remove/replace a relay?

 

if the light comes on when you start the car without moving it then the ABS relay on the CE panel is the most likely culprit,
buy a used relay from Ebay.
NOTE you can kill this relay by having the screwdriver touch ground with the battery still connected,
while removing the screw that anchors the ABS power wire at the LF under the PS tank