The picture poorly illustrates my question:

I'd like to replace the fixed front sight base on this gun with something like the YHM flip model that is two piece, and can be installed with the flashider in place, I believe.
So, question is, how do I get the current front sight base, handguard clip, and bayo lug off the gun without screwing things up.  The rifle has a 14.5 barrel with permanantly attached muzzle break.
Options I am considering:
Drive taper pins out of gas block.  Drive out roll pin on gas tube.
Try to cut through gas block with dremel rotary tool.   Realistically, don't think I can do this without gouging the barrel.
Is there a better approach I'm not thinking of?
If I can't get it off, should I shave it down to low profile by possibly removing bayo lug, ears for sling mount, and front sight post?

If it was me,after punching out the FSB pins and removing the gas tube..  I would run a hacksaw blade between the barrel and gas tube portion of the fsb and carefully cut thru the front and and back of the sight base. Once the top of the base is off you can pry the bottom half off?    

  YMMV