You wouldn't have to do much really. It's a bit of a beast, and with that fan pack would not be quiet, but it's more than capable of the job. You'd just need to have enough (hot plug) disks to do the job. If the server has a hardware raid controller, I'd use it to create a RAID1 (mirror) over a couple of SATA disks, then fill whatever space is left with much larger drives. You could use RAID5 on these, but that's often overkill for home use, so I'd recommend you just set them up in JBOD mode. Install your O/S on the mirror pair, then you have multiple options on how you want to manage the data disks;
Treat them as individual disks and balance your data across them manually
Use something like WHS2011 with Drivepool/Drivebender to create a single large pool of data
Use WS2012Essentials with Storage Spaces
Use a Linux distruibution with FlexRAID
Alternatively, you could use one of the many 'free' NAS options. This
is a good link explaining things.