Bike "repair"

I got a flat tire during my lunchtime ride today, and it was on the rear wheel. I guess it hadn't occurred to me, but changing the tire is a little more of a pain in the ass with a single speed. Not having done any bike work for a long time, I managed to completely screw everything up. I managed to pop one of the chain pins out (first time ever for that), and spent the next few hours trying to get it in. Predictably, the chain was too short -2 links :(.