Head to the church and take out the first wave of rocket troopers. After clearing it out, enemy TOW vehicles will arrive. Hop on top of them then take out their launchers. Use it against them. More enemies will appear. Just continue clearing them out until the assault team is deployed. Start by weaponizing their TOW launchers and clear up the rest of the opposition before the church takes further damage. Return to the church to complete this mission.
Heller against hell
After completing this mission, a new Blacknet mission will become available. (Operation Clean Sweep)