First, make sure that all text is using Courier or Courier New and is at the same point size (usually 10-12). Move your right margin so that you see roughly the right number of characters per line (usually 65-70). Then choose File / Save As and then choose the format "Text Only with Line Breaks". Save your file with the extension ".txt" to distinguish it from your Word format file.
After saving, open your text file using Notepad or some other simple text editor and look at the results. You should see a typical PG layout of the text--lines up to 70 characters long, a blank line between paragraphs and no indentation at the start of each paragraph. If so, you're done.