gabriel,
Since you're running a RAID 1 mirror, each disk should have the same data on each disk. There's some "magic" you can do to see a Linux* partition with Windows*, but the definite easy way would be to put the SATA disk in an external USB disk carrier and plug it into a Linux laptop/system and copy the data over.
The SS4000-E storage system software 1.4 provides greater than 2TB storage space by mounting multiple Linux type xfs data partitions, i.e. /nas/NASDisk-00002, /nas/NASDisk-00003 and so on. So, for instance, the public folder would be at /nas/NASDisk-00002/public. If I remember correctly, the user folders will be at something like, /nas/NASDisk-00003/gabriel.
Here's some hints if you need to use a Windows system:
Good Luck,
John