Modificando a classe do link "readmore"

change_readmore.php

<?php

function dkc_change morelink_class( $link, $text )
{
    return str_replace(
         'more-link'
        ,'leiamais' //removi a more-link
        ,$link
    );
}
add_action( 'the_content_more_link', 'dkc_change morelink_class', 10, 2 );