1) find access shaft.
2) fill tunnel with water
3) send in submersible drone to go down tunnel as far as it goes, and place explosives there.
4) detonate explosives. The incompressibility of water will channel the force of the explosion to blow any airlocks that have kept water from going further in.
5) if water level drops, repeat from 2.
6) if blast uncovers other access shafts, repeat from 1
I *like* your plan. Sounds good to me...
You forgot 1A: Pump in hundreds of gallons of bacon grease, film the operation and release those videos on the internet daily.
THEN proceed to step 2.
What are they going to do, get mad and start committing acts of terrorism?
I like your 6 step program.