TestLink

HI,
We are using Testlink version 1.6.2. We would like to upgrade to the new version 1.8.5 (or even 1.9).
What does it takes for us to perform the upgrade? Should we change the structure of the existing database?
What are the steps to be done?

Thanks

upgrade can be only done in this way

1.6.2 -> last 1.7 version
1.7 -> 1.85b
1.85d -> 1.9 beta

there is no way to do this not using the migration code provided with TL

use:
http://testlink.org/cvs_tarballs/index.php

to get older versions