I'm so frustrated I'm ready to throw the rifle against a wall.  I got two of the three pins out.  The third one gave me so much trouble.  I had to dremel and drill it because it mushroomed on me.  Now I realize that I have to take the flashhider off in order to slide the FSB off.  And there's is nothing that I have found to be more difficult than take a flashhider off.  I tried putting it in a vice to hold it (with a towel around it to protect the finish), but I still managed to marr up my rifle all to hell.  And now that I've pretty much destroyed the damn thing I haven't managed to budge the flashhider one bit....

Maybe it's permanently attached.....pinned welded etc....

2 pins hold it to the barrel. The third pin just holds the gas tube and taps out very easily.
I tapped mine with a mallet a few times and it slid right off.
Flash hiders are the only thing permanently attached and yours might be.
Lefty loosey, righty tighty.

Well, I just got done reblueing my FSB from a similar experience.

I ended up taking mine out and putting them back in about 8 times. (I'm serious)

Here's what I learned.

Use an OVERSIZED punch just to break them loose.  I think the best of was the 1/4" punch.  This made it easier not to slip off/mar the finish.

Lay the FSB on a rag, on the jaws of a solid vice (make sure backside of the pins are sticking through a gap in the jaws... duh).  Then make sure you aren't on the HG or anything.  Give them a stout WHACK with a decent hammer.  It's a steel peice so don't be scared of it, and I guarantee, you will end up marring it up a LOT more trying to baby it out then just getting serious from the get go.  Use decent weight hammer (I just used standard nail hammer) and you'll be good to go.

Gundraw

The FSB pins are sometimes tapered.  The small end will be on the left (as held in the shooting pos.) side.  The FSB must be supported by a block of 2X4 or the special Brownells plastic block.  The cupped end starter punch sold by Brownells is actually a 3/32" nail set which you can find anywhere.  Use a decent hammer, like a 16 oz. ball-pein.  A couple of good whacks should get them moving.  Follow up with a regular punch.

Good practice to remove the pins left to right even if they are straight pins.