The most convenient way to Pages documents to MS Word format would be to use the Pages app on Mac. If you do not have access to Mac or do not have some friend that has one, you will have to use some alternatives.
Windows users can try to install the free LibreOffice suite, but this might not be perfect option as some formatting might when the conversion is done. If you own Apple ID, you can try to convert your .pages document as a .doc file using iCloud and iWorks online.
Open PAGES file Open DOC file
Full-featured word processing and desktop publishing tool from LibreOffice suite
Mobile version of popular word processor from Apple
A word processor and layout tool marketed by Apple