How do you replace the cutting deck belt on a greenfield 28M707 ride on mower?

Remove the plug lead to avoid a start up. With the deck in the lowest position, take off cutter belt from the engine pulley by pulling it down below the pulley. It id as tight fit so perserve. Unscrew the bolt in the head of the idler pulley on the left hand side and remove the pulley, same for the right hand side pulley. Loosen the 2 outer nuts on the centre cutter pulley guide and remove the remaining nut at the front of the centre pulley. The belt can then be removed. Refit new belt in reverse order, run belt for about 30 minutes then check tension when engaged. If too loose then move the left hand bracket adjuster, or if really loose, put the bolt through another of the 5 holes. Belt is too tight if blades keep spinning when disengaged. Blades should stop spinning in about 7 seconds when disengaged.