I have searched the forum and found that adding SiteTree::breadcrumbs_delimiter = " | "; to _config.php should do the trick. However adding this line produces this error "Parse error: syntax error, unexpected '=' ".
In SiteTree the breadcrumbs_delimiter is a public static variable so does this mean that I can't just set it in my Page.ss file? Is that what static means when declaring a property in a class? I am still new to OOP so some of this doesn't make sense to me yet.