I just did the rotors on my 98 4wd 2500 Suburban. You need to remove the bearing hub assy to remove the rotors. To start,of course, remove the wheel. If there happens to be the metal clips on the studs, remove them. Next, unbolt and move out of the way the brake caliper. It is held on with two socket head bolts accessed from the back side of the caliper.
Take the nut off of the splined shaft that runs thru the middle of the hub assy. Then there are 4 bolts that hold the hub on. I believe they are a 15mm head bolt. They go thru the back of the steering knuckle to the hub. I turned the steering to full lock one direction, removed to bolts, then full lock the other way to allow easier access to the retaining bolts.
Note that you may have a wire leading to the hub assy. That is for the wheel speed sensor for the ABS. I followed mine up to a connection and took the wire loose there.
Then with a combination of hammers, punches, chisels, and penatrating oil I removed the hub and rotor assy, bringing the ABS wire with.
If you are having the rotors machined, leave it how it is, wrap the wire around the hub and bring it in.
If you are replacing the rotor, protect the threads on the wheel studs while you tap them out. You should now be able to replace the rotor.You can see from my pics that it is impossible to remove this style rotor without removing the hub.