You'd have to swap the UpdateProfilePhoto@handle method.
Put this in the booted() method of SparkServiceProvider
Spark::swap('UpdateProfilePhoto@handle', function ($user, $data) {
$file = $data['photo'];
$path = $file->hashName('profiles');
// We will store the profile photos on the "public" disk, which is a convention
// for where to place assets we want to be publicly accessible. Then, we can
// grab the URL for the image to store with this user in the database row.
$disk = Storage::disk('public');
$disk->put(
$path, $this->formatImage($file)
);
$oldPhotoUrl = $user->photo_url;
$user->forceFill([
'photo_url' => $disk->url($path),
])->save();
if (preg_match('/profiles\/(.*)$/', $oldPhotoUrl, $matches)) {
$disk->delete('profiles/'.$matches[1]);
}
});
I just copied the original method into it above. You'd just adjust it how you need it.