Simple: select the hyperlink and press Alt-F9 to expose the field codes in the document. Hyperlinks will look something like:
{HYPERLINK "https://www.msofficeforums.com/word/35596-force-line-breaks-screen-tips.html" \o " Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Maecenas porttitor congue massa. Fusce posuere, magna sed pulvinar ultricies, purus lectus malesuada libero, sit amet commodo magna eros quis urna. Nunc viverra imperdiet enim. Fusce est. Vivamus a tellus. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Proin pharetra nonummy pede. Mauris et orci. Aenean nec lorem."}
Everything after the \o is the screentip. You can insert line breaks as needed.
When done editing, press Alt-F9 to hide the field codes, then Ctrl-A, F9 to update the fields.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]