Quote Originally Posted by Jen
I'll give it a try. Soo, for the back wheel, you lift the lever to open the brake pads then release the quick release lever, take the chain off the back cassette and remove the wheel. Then, in my case for practice, remove the air from the tire and slip in a tire iron to start removing the tire, hook it to the spoke??? then remove the tire from the front of the rim by hand till you can get the tube out. Replace with new tube, put back on rim, inflate ( now or later) and put it back on the bike, hook up the chain to the cassette and go. Sounds easy, but can I do it? Not sure how to use the co2 cartridges.
You are almost there! To get the chain off the cassette, push the derailleur pulley forward toward the front of the bike and fiddle the chain off the cassette while pulling the wheel backwards. Confused now? It's a whole lot easier on a bike stand, but you can turn the bike upside down.

For the tire iron part, hook one tire iron like you described opposite the valve, and hook a second one a few spokes away. With the third iron, remove the tire from one side of the rim. Then you can take the tube off but the tire stays on the rim (one side).

I am not a fan of C02 cartriges. Always carry a small pump as a backup because no matter how well you know how to change a tire, if your CO2 cartridge fails, you won't be able to pump up your tire like a balloon.

Make sure your wheel is centered when you put it back on. Practice with someone around who can help if you need it at first. Your hands will get dirty.