download the file to your computer and save it somewhere you can find it. the button that has your username at the top of the page has a scroll down option. click 'settings'. scroll down to where it say 'Literature Author Tag'. click 'change author tag', then 'upload file'. once that's done just press save and you're done. it may take a few days for the results to be visible throughout the site.
no worries that was me not too long ago, i remember stumbling through this site blindly, calling up my friend who showed me the site at eleven at night and asking her how to submit something We've all been there.