Are you sure this wasn't always a plan to get rid of the Final Salary Pension ??
Tell them you're gonna take away the Equal Time Roster, then announce that the FSP is going as well. Get everyone worked up, then when its all about to hit the fan, suggest that you might be able to give back the equal time roster and everyone feels more agreeable.
Its an old trick wartime doctors used when they needed to take someone's leg off. Tell them they need both legs removed, then once the full horror has had time to bed in, advise that they might get away with just the one, and suddenly things don't seem so bad !