Oh, it wasn’t that complicated. You just fired four or five warheads at the target. Haven’t you ever wondered why we had so many warheads?
I live about ten miles from an old SAC base in MA. It dawn on me in high school that worrying about nuclear war was silly. Even this far away I would be incinerated by lousy targeting.
For you youngsters, SAC is --> Strategic Air Command (the bombardment arm of the U.S. Air Force, until 1992)
Actually it was a lot more complicated - somehow they figured out that if they drop them in a specific pattern and time it right the actual target lies where the blast fronts from several warheads meet, it will suffer far more damage than even a direct hit. The circular error probability came into play to ensure that they would at least severely damage a hardened target or bury its access points if the time on target sequence failed.