If you're looking to do this via a regular link instead of through AJAX or another type of form request you can set up a special route that will respond to a normal GET
request:
In your routes, define this in addition to the resource:
Route::get('user/{site}/delete', ['as' => 'user.delete', 'uses' => 'UserController@destroy']);
In your view:
Delete this user
In your controller:
public function destroy(User $user)
{
$user->delete();
return redirect()->route('users.index');
}