We are short the Jan 45-50 put spread which means we are short the 50 puts and long the 45 puts. On expiration both will go to parity at the end of the trading day. Since the stock is around $49.50, parity for the 50 puts is 50 cents, and for the 45 puts zero.
All we really need to do is buy back the short 50s before the close.
Assuming that the market will be neutral, the stock should be drawn to $50 a share intraday and when it is, those 50 puts will have little value--their price will drop. So when the stock makes a run up through fifty, we should buy them back. Going into the morning let's keep a 20 cent bid in mind. But unless the stock runs up big, we will buy them back by the close.
To remind you, the opening trade was selling this put spread for $1.90. Let's see how well we do closing it.