Hello I will help you with your question,
The ring is the ABS tone wheel and you will have to remove the hub to replace the stud as you will have to take the tone wheel out of the way.
The procedure to disassemble the hub is below
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If the races are corroded or worn you need to be able to get the races out and the easiest way to do this is with a slide hammer. Many auto parts stores have rental tools that end up to be rented at no cost when you return them.
There is a Recall notice for the center hubcap in that the dealer would replace the cap with a new design to keep water out of the bearings. You may want to call them with the VIN to see if this has been done, they can run a history on the vehicle and see if the recall is open.
If you don't see ant corrosion or wear on the races you can repack and reassemble, these bearings will last a good many more years if you keep the water out of them.
When you tried to ask this before were you trying to respond to an email?
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