They just need to lock worlds when they become full. It's as easy as that. They should have locked severs the moment they became full. This would force new people to other serves. They waited too long to fix this issue. Now they expect it to magically fix itself overnight. This will take time. They just need to keep the servers locked. They can offer a few more incentives like FC/ house moves for people to leave in groups. Eventually the population will drop down but this will take time. They just implemented the new transfer incentives a week ago. Give it time.