It was super quick and easy, I didn't do anything fancy and I'm pretty sure anyone could figure it out on their own, but quickly, here's what I did.
I traced the old cover, and by traced I mean I layed the old cover on top of my new fabric and cut, no pins or anything. I made it slightly wider than the original because it seemed to slide up on the sides at times. I had some bias tape laying around so I sewed that to the edge leaving a gap at the top, threaded the rope from the old cover through that with a large tapestry needle and pulled tight.
There you have it, started and finished quickly on a Saturday afternoon while the kids watched a movie and the hubs brewed some beer. Oh the beer, I'll have to tell you about the beer soon. I'm so glad he's back to brewing.