It may be of interest to access the disks from some other machine.
This is fairly straighforward if that machine runs some variety of Linux.
The physical interface is quite standard SATA, with power and data. Since the disk is a large spinning one, the power required is more than a mere usb connection can provide, but some of the USB-to-SATA adapters have a connector for 12 V power which can be used.
With this in place, the disk's partitions show up as RAIDs. Not directly as ext4 file systems. There are 4 such partitions.
The mdadm utility will allow these to become accessible.
Do apt install mdadm if it isn't already on the system.
Then mdadm --assemble --scan will make the system discover the raid details and generate four new disk nodes:
/dev/md1 /dev/md2 /dev/md3 /dev/md4
These may be mounted with the usual mount commands.
There may be an unmounting command, but the best way to close up would be to power down the working machine and disk, and not attempt to disconnect it while it is accessed by the machine.