1 - Attach an external disk to Server1 and then run waimportexport.exe
2 - From the Azure portal, create an import job.
3 - Detach the external disks from Server1 and ship the disks to an Azure data center.
4 - From the Azure portal, update the import job
Reference:
https://docs.microsoft.com/en-us/azure/storage/common/storage-import-export-service