How do I undo a file merge?

[Guest]

In the process of working on a new document for an instructor at this
community college, I needed to go to another instructor's file in order to
get a particular format. Instead of just copying the file, I decided to
merge it to the first instructor's new document. This, I have discovered,
was a big mistake! Now, I am unable to undo the new file with the file
merge. Any suggestions as to how this situation can be rectified?

 

[Daiya Mitchell]

Try closing without saving. Or deleting. I guess ctrl-z didn't work?

I suspect this page explains what happened, by the way:

http://word.mvps.org/FAQs/Formatting/PasteWithoutSectionInfo.htm

And possibly:

http://word.mvps.org/FAQs/Formatting/WorkWithSections.htm