Remove the mites with a small brush. Deposit them into a sealed bag, and dispose of them.
Remove any mold growth, which the mites are naturally attracted to, by brushing it off or putting the mold in contact with sunlight.
Store these books in a dry, hot space, whose conditions will kill the remaining mites off naturally. Setting a dehumidifier near them to a humidity level below 50 percent will deter the mites.
If the mites prove persistent, apply boric acid powder to them. Available in most pharmacies, boric acid powder should be used cautiously and in small doses.