Not sure what to explain... powerCMS should work on any web site, so that includes powerStore.
We will actually be integrating the two in the next version of powerstore, but there is nothing to it realy, just replace any content you want to come from powerCMS with the powerCMS reference just like you would when using powerCMS on any other web site.
What part do you need more explanation of? I think you can just follow the powerCMS documentation and use it on a powerstore site.