How do I Remove the brake rotor on a 98 dodge 2500 4x4?

REMOVAL - 1500/2500 FRONT
Raise and support the vehicle.
Remove the wheel and tire assembly.
Remove the caliper from the steering knuckle, (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/DISC BRAKE CALIPERS - REMOVAL) and remove caliper adapter assembly (Caliper Adapter Assembly).
NOTE: Do not allow brake hose to support caliper adapter assembly.
Remove the cotter pin from the axle nut. Remove the axel nut.

Remove the 4 hub/bearing studs found on the inside of the sterring nuckle. Loosen the clamps holding the anti-lock cable.

Tap on the axle to release the splines from the axle to the hub.

Carefully remove the rotor from the axle and steering nuckle taking care not to stress the antilock cable.
. Just to add to the removal of the rotor and bearing assy. Snap-on makes a socket like tool that goes between 1 of the 4 inner hub/bearing bolts and uses the power steering of the truck to loosen the hub assy. Cost around $30 bucks, but well worth it if your hub assy is seized or stubborn.