How can I release the variables xmlParser and parser safely in the function below?

- (id)callRestService: (NSString *) methodName : (NSDictionary *) params
{
    NSURL *url=[self getRestUrl: methodName : params];
    XmlParser *xmlParser = [[XmlParser alloc] init];

    NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:url];
    [parser setDelegate:xmlParser];
    [parser setShouldProcessNamespaces:NO];
    [parser setShouldReportNamespacePrefixes:NO];
    [parser setShouldResolveExternalEntities:NO];
    [parser parse];
    [parser setDelegate:nil];



    return xmlParser.dictionaryArray;
}