new_billing_method := `{
        "address": "This is the new one",
        "city": "el segundo",
        "country": "United States",
        "creditCardCVV": "123",
        "creditCardMonth": 5,
        "creditCardNumber": 4242424242424242,
        "creditCardYear": 2024,
        "firstName": "z",
        "lastName": "t",
        "state": "California",
        "zip": "90000"
    }`
    var m map[string]interface{}
    err := json.Unmarshal([]byte(new_billing_method), &m)
    if err != nil {
        panic(err)
    }
    // m is the new map[string]interface{}