Advice - not destroying my (now frozen but already cooked) prime rib

Long story short - I cooked the prime rib for the family on Christmas. Turned out very good - smoked on the Traeger. Immediately after Christmas we flew out of state, so I froze the slices we didn’t finish. Seeking any suggestions on how not to ruin the meat when I’m ready to finish the roast.

Thanks ahead of time!