You can see a post on this from @Nikki here http://www.hometalk.com/522754/i-turned-a-tire-into-an-ottoman - she links to her blog post which has instructions. There are also a number of amazing posts on this topic on Hometalk. Here's a quick search I did for you: http://www.hometalk.com/search?filter=tire+ottoman
http://www.thatwasawhat.blogspot.com/ has a good one. Love it!