just make sure they do not screw it up. tell them to line it all up before removing the belt and do not turn anything while the belt is off. the easy way to do it is to mark crank and and cam pulleys and belt. before pulling belt. remove belt count the teeth between marks and mark the new belt the same as the old. install new belt making sure the marks are lined up . there is no question to whether the belt is lined up or not if you do it this way. it does not even matter whether the engine is on TDC of #2 cylinder or not. but I would make sure it is so you do not have to fight with the cams trying to turn. again very simple and fail safe.