Solved it by hopping around a bit. The answer for any newbie that needs help is to simply download the “Code Snippets” plugin and activate it.
Next step is to go to the section to add a new snippet in that plugin, and paste the following code:
add_filter( ‘generate_leave_comment’,’tu_custom_leave_comment’ );
function tu_custom_leave_comment() {
return ‘PUT WHAT YOU WANT HERE’;
}
In the section where it says “PUT WHAT YOU WANT HERE”, you can change that to whatever text you want and it will replace “Leave a Comment” with your new text.