Download the PDF exporter for Microsoft Word, then set this as your page size:
85mm width x 114mm height
Make the margins o inches.
Pick a smaller font size — even 8pt should work.
Use single-line spacing (more is just not necessary).
Export as PDF, plug your Kindle into a USB port, and move the PDF onto the Kindle (it acts like a regular USB drive). If you put the file in the “documents” directory, the doc should be available just like any other e-text.