Trying to change the subscribe option on Cover.HBS

Hi there, I am trying to change the subscribe option over the cover photo on the Edition theme.

I have downloaded the theme and opened up the Cover.hbs file.

I need to remove the signup field and replace with a button that contains a link to my portal signup window.

Only problem is, I don’t know which lines of code to change and what to change them to here.

Any help would be greatly appreciated