How does the Supreme Court enforce a ruling that contradicts Congress or the President?

There are so many mistaken assumptions in this question that it's essentially unanswerable.

The branches of government are supposed to work like this:

legislative : makes laws

judicial : interprets laws

executive : enforces laws

So right away you can see that asking how the Supreme Court enforces a law is nonsense ... they're not part of the branch of government that does that.