Updating to Ossn 6.4 is in no way different as updating to Ossn 6.1
This is all the info I see on 6.4 I will do more research on how to upgrade it in the coming days.
https://www.opensource-socialnetwork.org/discussion/view/6048/ossn-64-lts-has-been-released. I open a topic on helping each other upgrade but that topic was closed with no reason why. Documentation on it seems hard to find other than paying for the upgrade which i just did.