Verified answer

Cranial Extraction specifically says "search target player's" so yes you can reroute it. You just cant change what is named with it as that is decided when the spell goes to resolve. This is because your opponent still controls the spell and Cranial Extraction doesnt actually target a card, only a player.

Wait, NO you cannot use Reroute on Cranial Extraction because Cranial Extraction is NOT an activated ability. If you used the card Redirect instead, then replace the word Reroute with Redirect in the above paragraph.