If you have one link page (ex. partnerlinks.php or partnerlinks.html) and you need to split it because you have too many links on it. The easiest way to do this is to create a new/next link page (ex. partnerlinks2.php or partnerlinks2.html) and take a half of the links from the first/previous link page and put them on your second/next link page.

Once this is done the last thing you need to do is to add a link on first/previous link page to second/next page and add link to second/next link page back to first/previous link page so users can find both pages.