How difficult is it to replace the rear spindle?

How difficult is it to replace the rear spindle? While replacing the bearing on my rear passenger side wheel my mechanic did something to ruin the spindle. He said he had a difficult time getting the bearing off the spindle and had to pry and use a lot of force. He thought he got away with no damage but a few days after taking it from his shop I started hearing a grinding noise whenever I took a right turn over 10mph.