Sorry, I don't get the plot. So Wilford came with a spare part and saved the engine he destroyed in the first place, but how does that lead to him taking power on the snowpiercer? Who put Andre in handcuffs? The head of the "police" is on Andre's side, who else is there to enforce Wilford's will? And then the police head Roche's family and himself got put in the drawer? again who will enforce that?
Also, why would Andre hide the fact that Wilford sabotaged the train? Shouldn't that be enough for him to rally the masses to his side?