Modify Labels & Buttons in WordPress Backend Boxes

The issue:
I was wondering how to write a plugin that changes the text displayed in some of the standard boxes on the edit post screen.

I am seeking to change some of the html and text displayed in the post_submit_meta_box-function without having to modify the core file.
The function is in edit-form-advanced.php and creates the submit-part of the editing form.

Is it possible to hook into the function that creates the box? Or do I have to overwrite it completely, or even delete the box and recreate it? And how can I do either of that?

Why I want to do that:
As I am building an event blog I am overriding the scheduled posting functionality and using future dates for my posts (as the date of the event). Now all I’d need to do is changing some of the text in the submit box to show to my users that they have to set the event date here. (for example change the text “publish on:” to “date of the event:” or something like that)

I’ve been using WordPress as a CMS for quite a while now, and I am jsut stepping into plugins. Until now I couldn’t find anything that helps me, so thanks in advance for any advice!