It's regular HTML with Smarty template engine so you can just proceed like you would on any other template page.
However please note that the PDF is also rendered from the same template and does not have a decent CSS support so you'll have to restrict your styling quite badly unfortunately.
Autoredirect won't work directly but you could inject some javascript to do that job for you through the use of a custom module. Not too hard but as always without decent documentation you'll waste an afternoon or two getting it to work correctly