First, Lens Plugin need to be upgraded: Can't view XML file in OJS 3.0 - #32 by Vitaliy
because of this problem: Can't view XML file in OJS 3.0 - #34 by Vitaliy
An example of JATS XML. which we produce for our journal: JATS2LaTeX/article_english.xml at jats2latex-0.5 · Vitaliy-1/JATS2LaTeX · GitHub
converters from docx to JATS (they are not perfect):
from PKP: http://pkp-udev.lib.sfu.ca/
or ours: DOCX to JATS XML converter