How do you fix rear wheel bearings on a BMX?

To fix rear wheel bearings on a BMX, start by removing the rear wheel from the frame. Use a cone wrench to loosen the locknuts and remove the axle, then take out the old bearings. Clean the bearing cups, install new bearings, and reassemble the wheel, ensuring proper alignment and tightness of the locknuts. Finally, reinstall the wheel onto the bike and check for smooth rotation.