The answer:
The surface must be screened or sanded to smooth it and then it is cleaned of all residues and recoated.
This can be done in a small area by hand.
Obviously, the depth of the scratches determines how much time and effort is involved.
If you are unfamiliar with this repair, you may want to seek help from wood floor care professional with experience ... — Lynn E. Krafft, ATEX/ICAN Associate Editor
lekrafft@juno.com