Change Shipping? Manually mark as shipped/delivered?

I have an order of someone local who paid for shipping.  On my way to the post office, I happened by them and just gave them their package.  I understand that I will get refunded for the label 15-31 days after it is not being used and I can refund the customer for the shipping they paid, but what are my options for completing this order?  How do I mark their order as shipped and delivered without the tracking completing the order?

If you click on an order, there should be a button that says "mark as fulfilled", that should do it.