Now the air can move freely out of the tyre, it's time to break the bead. This means unseating the tyre from the rim. You do this by applying downwards pressure on the sidewall of the tyre as close to the rim as you can. Put both knees on the tyre and use your thumbs to push down as hard as you can.
If things get tough this is a quick way to break the bead
http://www.webbikeworld.com/t2/bead-breaker/motorcycle-tire-bead-breaker.htm I change my own trailer tires this way too - I've found another way to break the bead - sometimes very stubborn on smaller tires. Take a car ramp, the type that you drive your car on to work underneath, and place the vertical edge on the sidewall of the tire/wheel (as the tire lays flat on the ground). Drive you car up the ramp until the bead lets go. Voila!
