Delete default products/categories

What's the easiest/fastest way to delete all of the default categories and products that come installed? I want to get rid of all this and was going to just delete them all but was getting a notice about resetting the master categories. Tried to search but didn't find anything useful. Do I have to go through each individiaul product and reset each one then delete it??? What if I just delete all the categories and ignore that warning?

menappi:

What if I just delete all the categories and ignore that warning?

That's what I do.

stevesh:

That's what I do.

You sure that's ok? I don't want to have any run into problems later one as a result but I don't want all these default categories/products cluttering things up.