The problem with the default WordPress Site Admin/Register code:
<?php wp_register(); ?>
is that the resulting html displays these links as list items. To stop it from making these list items and just only display the link as regular text is actually frustratingly, annoyingly simple.
What you can do, is to call wp_register() with an argument like this:
<?php wp_register('',''); ?>
This will get rid of the li tags. However you can also surround the links with any tags/text of your liking:
<?php wp_register('<div>','</div>'); ?>
See the original answer here: http://wordpress.org/support/topic/removing-list-item-from-wp-loginout-and-wp-register