I bought the bolt carrier group I needed to get my 300 BO build shootable from the EE (still need to buy it a charging handle of its own and optics).  I received it last night, and set out to headspace check the bolt to my barrel.  The extractor came off no problem.  I set forth to remove the ejector and found that the pin appeared to have not been set entirely then run into the lugs of the barrel extension.  I cannot think of anything else that would cause a burr like this.  I tried to remove the pin from the opposite side, but it wouldn't budge.  I then tried to force it past the burr hoping it was thin enough that it would just break off.  It didn't.  I did successfully break my punch though.  I then came up with the idea of reducing the burr with a jewelers file.  It is reduced with no harm to the bolt finish, but it cannot be removed completely this way without damaging the finish.  I put a couple drops of CLP on the pin last night and picked up a new punch this morning.  I'm hopeful that I can get a new pin locally, but who knows.  

Any suggestions on how to get it out?  I do not have an ejector removal tool.  looks like a great idea and seems like something I could possibly build (a lighter weight version).

Any tips or thoughts would be appreciated.  One thing I considered was putting a discarded piece of 5.56 brass in the extractor and using that to depress the ejector.

The ejector is under some spring pressure. Put the extractor, spring and pin back on the bolt, then hook the rim of a spent case under the extractor and use the case to depress the ejector then push the pin out. Be careful after you remove the ejector pin or the ejector will go flying. Release the case pressure on the ejector slowly and carefully. -W

Wools,
Thanks for the response.  A friend got the roll pin out.  It was mangled badly.  Ended up using a tiny drill bit as a punch.  Funny thing is a machinist here at work went after it the same way I did and bent his roll punch.

I can now check headspace, but will need a new roll pin.  Plan to stop by a shop on the way home.  I'll use the spent case to put it all back together.  Interestingly, I don't recall having any issues whatsoever tearing down and putting together a brand new PSA bolt just to check headspace on a build it wasn't even meant for (wanted to play with the gauges).

The ejector roll pin is 1/16 x 7/16".  The best "gun parts" source for one-off small parts is usually The Citizens Armory, but they're out of stock on this pin right now.

I had a similar problem with a new bolt that wound up worse than yours did.  I managed to bugger up the hole while trying to drill the pin out.  I have no clue why it wasn't coming out - no way to tell without having it out.  At least you know you're not alone.

And all of that agony was unnecessary. It is easy to check headspace without removing the ejector or extractor. Simply hook the rim of the headspace gauge on the extractor, and lever the gauge straight the same way you were advised to use a spent case to press the ejector into the bolt. If the chamber is in spec, the GO gauge will press into the chamber with one finger.

This may be true if you have experience doing headspace checks.  But a first-time user is going to have to mentally subtract the pressure applied to overcome the ejector spring from the overall pressure needed to close the bolt...  In other words, an experienced headspace gage user might be able to get away with not disassembling the bolt, but not a first-timer.  

And as a matter of course, I ALWAYS disassemble the bolt.  It is (almost always) easy, quick, and results in a definitive test.  My first 300 Blackout barrel wasn't properly chambered, and I could prove that by having used gages made by an established firm (PTG), and going through the process carefully, following all the steps, with multiple bolts.  While the vendor I got my barrel from was on my side on this, not all barrel sellers are, so returning a defective barrel can be a problem if you haven't done the test correctly.

This was my second time checking headspace.  Even in the future, I plan to disassemble the bolt as intended.  If nothing else, I want to know if there are problems in my equipment when they can be addressed easily, not out away from tools.  I can certainly appreciate everyone's own approach, but in the case of firearms and ammunition, I like to err on the side of caution.  Hasn't hurt me yet.

GHPorter, thanks for relating your experience.  It is nice to know others have been in the same place.

These days I use one of the ejector tools from Brownell’s.
I can do it without the tool, but the tool makes the job dead easy even with problem pins.
I also use a short roll pin punch which is less likely to bend when hammered hard.
Like GHPorter I always disassemble my bolts and have run into the occasional pin that looks like it was swaged or something on one end.