They'd need Southampton to beat either Everton or Swansea and then win their last game along with anothet Swansea loss. Highly unlikely but they've given themselves the most unlikely of chances.
They need Southampton to lose to Everton. A draw in the Southampton Swansea game. and the Southampton and Swansea to lose their final games.
Oh and they need to win their win final game of course with enough goals to have higher goal difference over Swansea.