Migrating from Baikal to nextcloud, How to?

Hello Community,
the old IT Admin installed Baikal as contact and calendar Server, I however want to get rid of Baikal since it is not maintaned anymore.

Is there anyway of importing all calendar items from Baikal to nextcloud?

thank you

Baikal is maintained again since a few months:

I moved for convenience reasons from Baikal to Nextcloud. I just did an export of Cards and Calendars and imported these into Nextcloud.