That pin is a bitch, but it is possible to remove. Some are worse than others depending on how overzealous Benelli got when staking around the ends of the pin. Plan on busting punches and definitely wear eye protection since punches are quite energetic when they fragment under hammering.
Another issue is the pin is such a small diameter that you can't really deliver a lot of hammer force to the pin without risking bending the punch. I did buy a set of short punches to get the pin moving. I've still broken these little punches fighting with that pin. I've broken tons of Starrett punches on that bastard. I usually use a 12 ounce brass hammer.
https://www.amazon.com/gp/product/B00H407C1O/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I've found the best way to drive it out is to clamp the rear sight housing into a padded vice on the sides of the housing. That way the pin is horizontal above the vice jaws and you can hammer on it going against the jaws. If you're hammering in a direction that will allow the housing to pivot in the jaws, you'll never get it out. Once the pin drifts a small amount, you can then switch to a longer punch to finish driving it out.
Getting the pin back in is much easier than getting it out. It will still be retained tightly by the staking present on the housing, so the risk of it falling out is almost non-existent.