BDS wrote:

I wonder if the bearings could be changed out as opposed to replacing
the entire turbo.

For automotive turbochargers specialized companies or the manufacturer
itself used to do this, they were then sold again as "reworked" for the
aftermarket. With mass production of turbocharged (mainly diesel-)engines I
don't think it's worth the labour any more for the automotive market. But
for aviation turbochargers, it might be an option, maybe best to check with
the manufacturer of the t/c directly. Though I don't know for sure for
aviation engines, I strongly doubt the local AP would be able to change
bearings on a t/c. The main obstacle would be to re-balance the rotor after
reassembly.

regards,
Friedrich