Rule 508.7 · Declare Attackers Step

The attacking creature isn’t removed from combat and it isn’t considered to have attacked a second time. That creature is attacking the reselected player or permanent, but it’s still considered to have attacked the player or permanent chosen as it was declared as an attacker.

While reselecting which player, planeswalker, or battle a creature is attacking, that creature isn’t affected by requirements or restrictions that apply to the declaration of attackers.

The reselected player, planeswalker, or battle must be an opponent of the attacking creature’s controller, a planeswalker controlled by an opponent of the attacking creature’s controller, or a battle protected by an opponent of the attacking creature’s controller.

In a multiplayer game not using the attack multiple players option (see rule 802), the reselected player, planeswalker, or battle must be the chosen defending player, a planeswalker controlled by that player, or a battle protected by that player.

In a multiplayer game using the limited range of influence option (see rule 801), the reselected player, planeswalker, or battle must be within the range of influence of the attacking creature’s controller. In the case of a battle, the battle’s protector must also be within the range of influence of the attacking creature’s controller.