Patterns are actually EPS files embedded in your document. It’s rare that you would want to unembed one of these files, but if the need arises, you can easily do it using InDesign’s Links palette - just select the pattern and choose Unembed File from the Links palette menu.
You can also unembed all patterns at once. Just select "Unembed all patterns" from the PatternMaker flyout menu.
However, if you later make a change to the pattern, the new pattern file will be re-embedded. So if you want to unembed your patterns, you might want to wait until you’re done making your changes to the patterns before doing it.