Watch a mountain bike repair expert explain how to remove the wheels of a mountain bike in this free online video on cycling maintenance.
One thing that's always, when you're taking off your rear wheel, and this goes for if you have disc brakes or if you don't have disc brakes, is that you want to always take it off in a consistent gear so that you know which cog back here to put it back on. With this kind of dérailleur. The Shramer dérailleur, it's hard for the dérailleur to swing away, so I move it to the fourth cog down always, 1, 2, 3, 4, so I know where to put it when I'm reassembling the bike. Same thing here, we've got a quick release lever. I flip the lever open, the when just naturally drops right out and now you can see we have the same sort of setup that we had with the front wheel, except we have a gear cluster on this side. So, putting one of these back on is the same thing. We want to make sure that the rotor is lined up in the caliper, we want to make sure we put the chain on properly on the cogs. Remember, I took it off on the fourth gear down, so I want to line it up here on the same gear to make it easy to line back up. I'm looking here from the back to make sure that my rotor is in the caliper correctly, and it is. Give it a little tug up like that. And now I can just close up the quick release lever, give the bike a quick pedal, make sure it shifts okay, and we've removed our disc brake wheels and put them back in. So that's the gist of it.