Remove all tags from links in header

On my site (and others I’ve seen), when you mouse over any link it provides an alt information, usually just a repeat of what the link is titled in the first place. This has been fine until recently, but now I’m trying to make Pages that roll up into a Parent Page, and the alt information that shows up is blocking the ability to see what the below links actually say. Can anyone help me learn what kind of information I’d have to remove from the theme and where to do so?

I’m assuming I’ll have to edit the theme itself, most likely in the header section, but I’m not sure what I should be looking for. Any help would be appreciated. Thanks!