I played with it. (I don't work for Touring Plans I promise) and what I did was go to modify and then add another one. Took about 20 seconds. So for example the first ride on my plan was Astro orbiter. Once I had completed iit and wanted to uncomplete it, I hit modify and changed astro orbiter from one to two. Then reoptimize. I don't think I've ever done that in real time. I'm more likely to skip steps of the plan altogether as I go.