Just wondering, is it possible to use just my father's teeth from his dentures?

No: I am not certain what you mean but the answer is still "no." I do not know if you want to put your father's dentures in your own mouth or use the teeth to make dentures for yourself. Weird.,

How?: Do you mean to use your father's dentures? It is not likely that that would fit you.

Denture teeth: First of all dentures are custom made to fit the wearer and only the wearer, so the denture bases (the pink part) will not fit you. Second, it would be highly labor intensive (expensive) to remove the teeth from your father's dentures than to use a new set. Possible, yes. Advisable, no.