I've got something about it on my email somewhere. I'll edit this post when I find it for you. I Think it also has the bit about single-speeding if your unsure on that. edit: You would need: Chain whip Cassette lockring tool (and spanner/ratchet to turn this) Single speed sprocket Spacer kit Chain tensioner (or you could use the existing derailleur) 1. Take your wheel off of the bike, and put the lockring tool into your cassette lockring. 2. Using the chain whip around one of the cogs to stop it moving, turn the lockring tool anti-clockwise using the spanner/rachet. 3. Take the lockring off of your hub, and the cassette should just slip off the cassette body (if it gets stuck, which sometines happens, you should just be able to tap it off with a mallet) 4. Next you need to slide a spacer, then the cog you want, then another spacer onto your cassette body, and tighten the lockring back up If you get any problems, leave a comment on my profile or add me to msn (address is on profile)