I just purchased a 1978 Kubota tractor. I know nothing about tractors. It won't turn over, so I assume the battery is bad(but the lights work?) I can see the battery in the front grill, but can't seem to get at it. It looks like the front grill just pulls down, but it won't budge. Before I force it open, does anybody know exactly what the trick is to get at the battery? And if somebody thinks it could be some other problem I'm taking advice.