No need to press it out or off but there is more to it than just 3 bolts.
jack up car, use jack stands, remove tire
you will need a 34mm or 36mm deep impact socket to remove the wheel hub nut in the center.
Remove the caliper and pads, then the brake rotor.
Now you can remove the 3 bolts for the bearing assembly, the top center is tough to get at, you will need to loosen it off half way then rap the center shaft back for better access to remove the bolt (you will see once your head is in there).
Install in the reverse order, put a little dab of grease on the end of the half shaft splines before inserting into the bearing.
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Same thing applies to your Aurora Oats, I had to change my hub and it was a total PITA, the wheel speed sensor ring was stuck inside the spindle, making it a nearly impossible DYI job. I hope for your sake everything goes ok.
G-body cars are notorious for bad wheel hub. Everyone I know that has a 2000-20004 Bonneville, Classic Aurora or Seville has had an issue with a hub just short of 100K miles.