I don't know any automatic way. My suggetsion is to carry out a new installation of the older version, and then migrate the data from your current database to the new one. You also have to reinstall your customizations.
Na realidade eu ainda não passei por isso, mas conversando com um amigo desenvolvedor surgiu a dúvida e pensamos como é possível que você resolva esse tipo de problema.
De qualquer forma sua resposta é uma opção se não houver opção de automática.
If you're looking to downgrade from one version to another, such as going from 7.5.2.1 to 6.5.20, there is not an automated process, it is not supported and not recommended.
A very high-level overview of this process would be as follows:
1. Install the older version on your web server. 2. Extract the database from the newer version and import it into the older version. 3. Extract or recreate the code customizations from the newer version and deploy them into the older version.
If you're looking to change the Edition you are using, such as going from Enterprise down to Professional, additional information is available in our Knowledge Base.
