I've never actually been stuck at the side of the road with my Harley, but I've changed the tyres enough times not to be worried about the possibility. First of all you can use slime (or something similar) to reduce the possibility of a puncture in the first place. I know a lot of people are against this, but I'm all for it. If you carry an electric pump you can often make it to a more suitable place to stop and repair a slow puncture. My bike will lay quite happily on the crash bars while I remove either wheel. Although my tyres are tubeless I carry a spare tube to fit if required as well as a tubeless repair kit. I would always aim to fit a new tube at the roadside and repair the old tube when more convenient. If a punctured tube's got slime in it I'd probably replace it with a new one a soon as I could. The hardest job at the road side would probably be breaking the bead if the tyre has to come off and you often just have to improvise, I've used all sorts including jacking a car up on top of the tyre (after suitably protecting the vulnerable parts). You can also try riding the bike a short distance with a flat tyre until the bead breaks.
Practise changing your own tyres at home before you leave.
Grant and Susan's DVD on tyre changing is a wealth of useful information even if you think you know it all. (Like I did before I was given it!)
If you think you are too small to make a difference you have never spent the night with a mosquito.