Example for updating all documents where name is equal to "John":
$filter = ['name' => 'John'];
$document = ['name' => 'Mike'];
$bulk = new \MongoDB\Driver\BulkWrite;
$bulk->update(
$filter,
$document,
['multi' => true]
);
$result = $manager->executeBulkWrite('database_name.collection_name', $bulk);