[V8] O2 Sensor HELP!

[Stafford, Kenneth A.]

Ok, I've decided to replace my O2 sensor--got the Ford part.  Now does anyone
know how to get the stinking thing out??  I shudder at having to remove the
X-pipe--all the exhaust flange screws are totally rusted and will certainly
snap off if I try to get them loose.  I have the regular heavy duty O2 split
socket tool (and have installed hose clamps to prevent it from opening up).
I have applied MASSIVE torque to the tool, but don't seem to be getting
anywhere.  Anyone got a BTDT?  Should I try heating with a torch?  It have
sprayed it with WD-40 and smacked it along the threaded nipple.  I'm
considering drilling a 1/4 inch hole through the hex so I can get a rod in
there to turn it (when the rusted hex eventually rounds off from my wrench
efforts).  Looking for some sympathy and suggestions...
 
Ken
91 V8Q 200K miles (at least 90K and 7 years on this O2 sensor)