I haven't had to change one for years. The worst one I had to do was on a busy road in Germany - on the way to Hamelin (as in The pied piper). In town, I was lucky to meet a man who worked as a translotor, and he directed me to a tyre depot where he assured me the owner was English. Unfortunately the owner was on vacation, so I had to explain in very poor German that I needed a new tyre. However, I got everything fixed OK at a very reasonable price.
It surprizes me that so many people have no idea how to change a wheel and have to wait for breakdown services to rescue them! Even more, it angers me that so many new cars have NO spare wheel at all.