You have to play in a Silver League conference championship game, priority going to those who win, and then more so to those who continue to win the entire league.
If nobody in Gold sells there team, then the bottom 8 gold teams (4 in each conference) get demoted and the 8 silver champions win.
If gold teams do sell (that weren't otherwise being demoted), then championship runner-ups get moved up according to the old tiebreaker rules (record...then points allowed, etc).