There are great instructions for learning to change a tire right here on TE.
http://www.teamestrogen.com/content/asa_levers

This is what I used to teach myself. I printed them out, took the wheel off my bike, sat on the patio and did it over and over until I could do it. I did use my levers though. They are a dandy little tool.

As far as riding solo, I do a lot. Like Indy, I am sure that I have my RoadID, cash, food and a cell phone. Even when I ride with others, the "others" are usually the guys, ie. DH and friends, and I'm still riding solo since I get dropped on hills and can't catch back up. I'm always just out of earshot of the conversation and they don't always stop and wait where I think they should But that's the subject of another thread. I sure wish I lived in an area where there are other lady riders.