Is there a way to change the content of the discount 'popup' box?

When the discount box comes up, there are a couple of issues.

First, I don't want the button to say "Download". The link takes the user to my store page (on gumroad). I'd like to change "Download" to "Buy Now" or something like that.

Also, it's quite scrunched. Can I change the size. And maybe the font too?