Breach the next door open and quickly take out all enemies in front of you. After the breaching sequence, take cover and take out a few more enemies. If your Overkill meter is fully recharged at this point, it will be a good idea to use it now. Keep mowing down enemies until a cartel chopper appears. Keep shooting at that chopper to quickly recharge your Overkill meter. Once it is dealt with, engage more enemies and a chopper will appear again. Do the same thing to destroy it and trigger a scene.
After the bell tower crashes down, head to the destroyed house and make your way outside. Engage more enemies in the train yard and continue to the objective marker to complete the section.