All I did was take the cushions off of the chairs (4 screws, would have been much easier if I could have found the right bit for the power drill but doing it by hand worked). Set the cushion on the fabric and eyeballed it, then cut the fabric, stapled it on (with a heavy duty stapler), put the cushion back on and screwed it back into place. Done!
Before and After:
Keep in mind this is one of the "clean" cushions.
This was some great indoor/outdoor fabric that is also stain resistant and water repellant...um, translation: "perfect fabric for a chair in a family of 3 young, MESS prone boys!"
And some step by step (kind of):
Cut fabric, again I just eyeballed it.
Staple one side, then staple the opposite side pulling tight as you staple.
Do the same for the other two sides, leaving all 4 corners for the end.
Staple all four corners nice and tight.
Trim the extra fabric.
There you have it, screw it back on to the chair and finished!