The plate has a bearing inside and is mounted to the suspension arm and axle shaft. You cant get the plate off by itself. You have to remove the upper and lower ball joints and pull the knuckle and hub/ bearing unit all together.. It then takes a 20 ton press to push the parts apart.
this photo will give you a basic idea of construction. The vertical cast arm is called the knuckle. The bearing is pressed into this, and the hub (5 stud plate) is pressed into the bearing.. Snap rings hold everything in place. It does NOT come apart on the truck.
There is supposed to be a wheel stud access plug in the dust shield. You can use a punch to remove the plug. Then you will have an access hole large enough to fit the stud through. The hole is located behind the parking brake shoe adjuster and appears to be the same hole that would be used to adjust the parking brake. You need to remove the rotor, then remove the parking brake adjuster and bottom spring before punching out the cover. The manual suggests the plug can be reinstalled.
If you want a PDF of the procedure from the factory service manual that shows images, send me a Private Message with the specific request.