Remove content permissions metabox added by Members plugin.

gistfile1.txt

/**
 * Remove content permissions metabox added by Members plugin.
 */
function prefix_remove_members_metabox() {
    remove_meta_box( 'content-permissions-meta-box', 'post', 'advanced' );
    remove_meta_box( 'content-permissions-meta-box', 'page', 'advanced' );
}
add_action( 'add_meta_boxes' , 'prefix_remove_members_metabox', 9999 );