Usually when we talking about the Fed printing money, we're speaking metaphorically. Most money the Fed "prints" these days isn't actually currency; it's just an electronic representation showing that somebody has a certain amount of money in their account. But the government does still print actual, physical bills.
Simply put: Republicans agree not to vote on a replacement for Ginsburg until January; Democrats agree not to pack the Court.
2016: Fill it. 2020: Don't fill it.