The dirty little secret to rescuing a failed project is breaking the rules. I don't mean the regulatory or compliance variety, but those that get in the way of a project being delivered (read: the organization and its people). To get a project back on track, lifecycle standards, documentation, and petty resource issues must be, for the most part, ignored.
Civilian and military rescue teams don't bring in committees to get their jobs done, they just do it. Yes, there's some planning involved, but it's acute and focused on the problem in front of them. Action is the key to rescuing a failing project...and that sometimes means breaking sacrosanct rules.