|Make several copies of the file in Explorer:|
Select the file > hit Ctrl-C > hit Ctrl-V > hit Ctrl-V > hit Ctrl-V > hit Ctrl-V > hit Ctrl-V
Try whatever seems logical to you on the copies. If you screw up you still have the original document. Alternatively, try copying the pages you want to keep into a new document.
I think in Word you can tell it where to start page numbering. Search Help for "page numbering".