can I chage url for register_post_type

It would help if you listed your $args array, but, the portion you are looking for is under ‘rewrite’. Here’s the way I like to build an $args array for registering a post type:

// set up the labels
    $labels = array(
        'name' => _x('Archived Jobs', 'post type general name'),
        'singular_name' => _x('Archived Job', 'post type singular name'),
        'add_new' => __('Add New'),
        'add_new_item' => __('Add New Job'),
        'edit_item' => __('Edit Job'),
        'new_item' => __('New Job'),
        'view_item' => __('View Job'),
        'search_items' => __('Search Jobs'),
        'not_found' =>  __('No Jobs found'),
        'not_found_in_trash' => __('No Jobs found in Trash'), 
        'parent_item_colon' => '',
        'menu_name' => 'Archives'
//set up the rewrite rules
    $rewrite = array(
        'slug' => 'archives'
//build the arguement array
    $args = array(
        'labels' => $labels,
        'public' => true,
        'publicly_queryable' => true,
        'show_ui' => true, 
        'show_in_menu' => true, 
        'query_var' => 'archives',
        'rewrite' => $rewrite,
        'capability_type' => 'post',
        'has_archive' => true, 
        'hierarchical' => false,
        'menu_position' => null,
        'supports' => array('title','editor','author','comments')

The portion of this you are looking for is the $rewrite part, change the slug to whatever you want (url friendly of course, no weird characters or spaces). You may even wish to put slashes in there. In my example, a URL reads: