Soon after the farmhouse, look around to collect some ammunition and buy more items. After that, go to an opening where you see a lever. Go up to it and switch it to the right to fight El Gigante (recommended) or switch it to the left to face more
chainsaw wielding villagers (extremely difficult). If you select to fight El Gigante, aim at the rock at the top ledge until he is underneath it and fire. Use the same tactic on the one you dealt with earlier.