as far as i no if u use a scraper to accuratly mark the cas position before taking it off, put it at TDC then take off belts, line new belt marks up with dots on the cam gears and crank gear, turn over twice by hand, make sure is all lines back up, then re install everything else, there isnt much need for a timing light,
in saying that, a super cheap auto timing light is very cheap, use it and take it back the next day, get refund.