How do I remove a Glock front night sight

[Wikma Flintstone]

I was going to replace my front sight on a Glock 27 and instead of the expected hex nut, I found this; (sorry for the crappy pix)

I'd like to remove the sight without damage. Who knows, maybe I will not like my new sight. How do I do it?
Thanks

[swifty]

It is staked in place and meant for one time use. Use a punch and hammer to remove the sight. If you are careful, you might be able to reuse the sight. But expect to buy a replacement.

[G-forceJunkie]

If you remove it, its junk. Those two punch marks are "stakes" that flared out the metal to hold it in.

[peter95]

woah... Good luck. Punch it out.

[lazyworm]

hold it with a pair of pliers and twist to pop it out.
Don't expect to reuse it regardless which method you use.