Dave.........you will not be able to get them out. You might have to take off so much wood that it will damage the floor.
The newest floors in our house are 100 years old - believe me - they have all had a life! We just started refinishing them - and rather than try and make them look new - they are just being light sanded - in some cases restained a slightly darker color to even them out - and then varnished. All of the stains, chips, nicks, gouges and scratches are staying - and I must say they do look very good.