If it is an IBS type deck then go from the drive pulley/shaft all the way along the back to the large silver idler, from there up to the centre blade, then back to the left blade (next to the idler) from there around (in and out) through the little black tensioner idlers and back onto the main drive pulley / right hand blade.
It is easier to get it all laced up except for the centre blade, then just run it onto that one by pulling on the long back run while feeding it on. (saves nipped fingers) good luck.
Paul
March 2010