How do you change the front hub bearings in a 2001 2x4 Blazer or what is a fair repair shop price for this job?

You can't replace just the bearings. The wheel hub assembly is replaced as a whole unit. The cost of the assembly should range between $150 and $175. The labor to do the job should probably be an hour. Typical hourly rates are $60 - $100 an hour. The job is simple enough to do yourself if you have air tools. The shaft can get stuck to the inside of the assembly and an impact hammer is needed to push it out.