If they're the same as other ARs they use taper pins. You have to determine which side is smaller and drive them out from that side using a punch (concave works better) and ball peen hammer. It can still be difficult and frustrating even if you're doing it properly. Support it the best you can with a piece of wood that has a hole drilled in it for the pin to fall out.
I wouldn't drill them out if it can be avoided. Someday you may want to sell it and you'll find more buyers if the front sight is intact. These sights are not interchangeble, once you butcher it you cannot install another FSB in its place unless you're very lucky and all the stars are in alignment.