Tornare a HFS + da APFS

Recentemente ho sentito parlare del nuovo file system Apple. Certo che volevo provarlo. Così ho spostato tutti i file su un disco rigido esterno per sicurezza ... E accidentalmente l'ho passato ad APFS ... Come annullare le modifiche?

$ diskutil apfs createContainer /dev/disk1s2
Started APFS operation on disk1s2 Data
Creating a new empty APFS Container
Unmounting Volumes
Switching disk1s2 to APFS
Creating APFS Container
Created new APFS Container disk1s2
Finished APFS operation on disk1s2 Data

$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *240.1 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh SSD           239.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

/dev/disk1 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:                 Apple_APFS                         999.9 GB   disk1s2

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS Untitled                499.8 GB   disk2s2

/dev/disk3 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        +25.2 MB    disk3
   1:        Apple_partition_map                         32.3 KB    disk3s1
   2:                  Apple_HFS Data Rescue             25.1 MB    disk3s2