You could File > Export them into a few different formats, but depending on how complicated the document forms are, the results may not be pretty. The answer really depends on what format you need them to be in instead.
You could also try one of the many third party products on the market (e.g. http://www.processtext.com/abclotusnotes.html)
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You may consider this tool as well:
Take a look at these screencasts (You can see how to convert a group of selected Notes documents to PDF – creating either a single PDF Package or separate PDF files):