Add other payment method

Hi all, i'm working with the version 0.6.5, and i need to add other payment method,
Whot steps I must follow to acomplish this?????

Same here, I need to integrate AlertPay to it.

any development help is apriciated

Carro
-Catalog
  |-Language
  |  |-English
  |      | -Service
  |          | -Payment
  |                  cod.php
  |                    paypal.php
  |-Service
        | -Payment
              cod.php
              paypal.php

You have to agregate in this two location new files, wich will be your new payments.
Notice you have to modificate catalog/service/newpyament.php archive
the class contructor and the update, i follow paypal.php as example

I hope this can help you