I want to edit this code:
this.link = $('<a>Directions</a>').addClass('mapplic-tooltip-link').attr('href', '#').hide().appendTo(this.el);
to open in a new window. I've looked online but I don't know how to edit this. Any help would be much appreaciated.
try this
this.link = $('<a>Directions</a>')
.addClass('mapplic-tooltip-link')
.attr('href', '#')
.attr('target', '_blank').hide().appendTo(this.el);
just add another property attr to your link with the target key and blank value.