You'll have to remove the calipers and rotors but not the bearings. They can remain in the rotor. (Although it would be an excellent time to repack the bearings.) The outside one will come out anyway.
Unbolt the caliper and hang it outta the way, remove the castle nut, the outside bearing will come out, slide the rotor off the hub and then the sensor with the dust plate. There's a small bracket bolted to the upper control arm that holds the wiring away from the wheel. The sensor has a connector up next to the frame rail where it will unplug. Be careful with the connector, don't break the small retaining tang.... | 
