Follow the road and head to the marked spot to trigger a scene. After the scene, you'll have to choose whether you'll have to take the lower or upper paths.
Boost your partner over the gate then follow the trail on the right. Be careful since while you're separated, you can't be revived when you're wounded. Take cover and take the enemies out systematically. Use your Overkill meter once filled and there's a lot of targets to shoot at so you can get higher cash rewards at the end of the section. You can keep shooting at the vehicles along the way as well to make them explode and take out the enemies hiding behind them. Once cleared, follow the trail down to the chapel and meet up with your partner. Enter the chapel and after the scene, proceed forth to complete the section.
Go over the gate by having your teammate boost you up. Once inside, move forth as you clear the area of enemies. Use your Overkill meter once filled and there's a lot of targets to shoot at so you can get higher cash rewards at the end of the section. You can keep shooting at the vehicles and explosive barrels along the way as well to make them explode and take out the enemies hiding behind them. Once cleared, follow the trail down to the chapel and meet up with your partner. Enter the chapel and after the scene, proceed forth to complete the section.