I've worked on this and I think I've sorted it. I had the same question as Uendi so will answer that as well.
1. Create a template page (see http://codex.wordpress.org/Page_Templates)
Do this by copying page.php in your theme folder and name the copy - let's call it mynewsletter_page.php. Edit it so it says at the top:
Template Name: My Subscription Page
2. Add the code MailPoet says to functions.php, editing the wording to say what you want.
3. In mynewsletter_page.php after
<?php the_content(); ?>
<?php echo mpoet_get_undo_unsubscribe(); ?>
4. Create a new Unsubscribe page and this is the important bit: at the bottom right in Page Attributes choose the Template called My Subscription Page
5. If you preview this page here, no unsubscribe information will show but, instead, save it and preview it in MailPoet, Settings, Basics, Unsubscribe page, Unsubscribe (assuming that is your page's title).
6. You can go even further if you add to your template the code. at the bottom of http://support.mailpoet.com/knowledgebase/customize-your-confirmation-pages/. Then you can have one page for both subscribing and unsubscribing.
I hope that helps and that I haven't made any mistakes!