Add a line break on nav bar

Hello…

I have a problem trying to add a line break on each nav bar option..

Im using this theme: https://themes.livingos.com/2008/03/04/livingos-epsilon/

The probleits that the page′s names are too longo so they dont have enopugh space there. For this i want to add line breaks on them.

Its possible?

Thanks
Andres