Solved without overriding the archive template.
Add the following snippet in the functions.php
.
add_action( 'pre_get_posts', 'new_sort_order');
function new_sort_order($query){
if(is_archive() && is_post_type_archive( "post_type" )):
//Set the order ASC or DESC
$query->set( 'order', 'ASC' );
//Set the orderby
$query->set( 'orderby', 'title' );
endif;
};
If you want to change the order to all the posts just remove is_post_type_archive
from the if
statement.