So, obviously on the first step, when you are removing the rear gear cluster cassette from the back of your bike, is removing your wheel. So, most bikes that you're dealing with have a quick-release rear wheel, so it's a cam action lever, meaning you don't just spin it up like a wing nut, instead you pull on the lever to release the tension, and it just drops right out all quickly. You want to make sure that you remove everything from the chain smoothly, and remember what gear if you've taken your rear wheel often. So, now my rear wheel's off. You can see we've got nine speeds here. And, quick release has to come out. So just unscrew it because it's screwed together and put this aside. And now we need to focus on what the special tools are that you need to remove this. You can see that this little toothed area here--it's called a lock ring--you need a special tool called a cassette lock ring tool. This one's nice. It has a little protuberance on the end which sticks into the axle so things mesh up well. So you can see that's in there, it allows me to move everything around. But, you can see, it's marked right here. To lock the lock ring on, you rotate to the right--if I move to the left, everything spins, so I also have to use a tool called a chain whip, which is just a bunch of chain that goes on the cassette to allow me to move the lock ring against it. So now I take an adjustable wrench to hold the lock ring and work one tool against the other, and I can now take off my cassette.