Most pauses in a beamer presentation are used just to uncover more text. If this is the case, then the last overlay for every frame contains the full contents of this frame. You just need to delete all previous overlays and keep the last one.
If, on the other hand, there are overlays which contain information that is not retained in subsequent overlays, then it's not clear what you need to do. Probably, you'll have to keep those overlays too.
In any case, I'm afraid this process has to be manual; I don't know of an automatic way to do what you want, starting from a PDF file.
To extract just a number of pages from a PDF file, you can use a tool like Acrobat Professional, or various tools from the
pdfpages package on Linux (
pdfjoin may be useful).