Import message archive (embedded-db --> MySQL)

I have an existing OpenFire installation using the embedded-db, and a new installation using MySQL instead.

I have already used the import/export plugin to transfer users, and I manually recreated groups on the new server.

Now, I would like to transfer the message history/archive, but I’m not sure where to begin. Has this been done before? Does anyone have any advice on how to achieve this?

Thanks,

Scott