What kyle said^ soak the pins in some pb blaster or something and make sure you tap the pins out the right way! Don't be afraid to hit them hard, they're in there tight
If you are looking to pin it in place then it typically is beyond the scope of homebrew Smithing.
The FSB must be held in precise alignment while the fsb is drilled/reamed.
A jig or fixture is best.
I do them all the time, PM if interested.
Is the gas block pinned on now? I believe you drive the pins out from right to left when looking from the butt of the rifle. I think they are taper pins .