Peter has a box of old hard drives and they have data on them. How can he get the data off and put it on a central server? Leo says that he can get a universal drive adapter from Newertech, that can plug into and power the drive without installing them. Then he can see what the data is on the drive and move it. He can then get a network-attached storage device (NAS) to put them on. Leo uses one from Synology for backing up his data and act as a media server for his videos and photos. Great for large archival storage because they have multiple drives that can be redundant.
Once he's moved all data, he can then wipe the old drives to prevent any data from being lifted. He can get a big giant magnet and wipe the drive. Or he can use Derick's Boot and Nuke to write over the data several times to reformat the drives. BleachBit is another. But DBAN is free. He can then sell the drives or donate them. Or, he can take the drives apart and remove the platters and destroy them.
Check out Peter's amateur radio website, Great Los Angeles Amateur Radio Group at glaarg.org.