You would need to edit your theme files. You need to search each files looking for something along the lines of
<p>All Posts of: <?php the_author_posts_link(); ?></p>
and just change that to
<p><a href="https://wordpress.stackexchange.com/questions/70227/<?php echo get_author_posts_url(get_the_author_meta("ID')); ?>">All Posts</a></p>