If you'll calculate the RPM of the wheel bearings at 100 MPH (a speed you'll agree is ridiculously uncommon) you'll see that it's running quite a bit slower than a normal 1725 RPM electric motor... and those run for decades on cheaper bearings. So changing the bearings is unnecessary, and involves a lot of measurements and shimming you can't do.

What you DO need to do is refresh the bearing grease. That only requires removing the seals and pumping in new grease. Try that instead.