Read:
http://www.advrider.com/forums/showthread.php?t=50717
Or watch the above videos.
I actually just did a tire change by myself for the first time this afternoon. I've swapped tires 3 other times already on this bike, but this was my first solo job.
Take your time. It should be a little tedious, but not hard. If its hard, you're doing it wrong.
Soapy water on the bead and rim helps everything slip together.
Check what your iron is grabbing before you start pulling on that iron, make sure the tube is clear. Make sure the tube is partially inflated so that it doesn't get twisted, and before you set the second bead check again that the tube is clear and not twisted. Nothing worse than having to do it twice because you didn't check.