Workflow for users to download files?

Try adding this to your theme’s functions.php file

function Get_curPageURL() {
    $pageURL = 'http';
    if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
        $pageURL .= "://";
    if ($_SERVER["SERVER_PORT"] != "80") {
        $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
    } else {
        $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
    }
    return $pageURL;
}


add_filter('gettext','custom_login_to_download_msg');

function custom_login_to_download_msg( $input ) {
    
    if( !is_admin() && 'You must be logged in to download this file. <br/><br/><a href="%1$s"><strong>?† Back to %2$s</strong></a>' == $input  )
        return 'You must be logged in to download this file. <br/><br/>
            <a href="<?php echo wp_login_url(Get_curPageURL()); ?>" title="Login"><Strong>Login To Download</Strong></a><br/><br/>
            <a href="%1$s"><strong>?† Back to %2$s</strong></a>';

    return $input;
}

Which should give you :

And the Login to Download Link will start the download automatically once they are logged in.