Migrating Zimbra IM accounts to OpenFire

[nameless']

Hi,

I have a Zimbra Server (6.0.8), and planing to migrate to 7.1 soon.

As I seen the Zimbra IM features will be dropped in the future, I'm planning to move to OpenFire, as this instant-messaging feature is widely used in my company.

My questions is :

- How can I export each contact list of each person, and then re-import it to my OpenFire server ?

I searched a lot, but didn't find anything revelant

Thanks for your answers