Restore Data from a really old tape

Hi,

We have a ton of old tapes from a previous backup (not exactly sure what version, but it's probably Netbackup 4.x, running on AIX). Everything (master/media server, tape library, tape drives, backup software) have all be decommissioned years ago. Tapes are the only things we have now.

We currently use Netbackup 7.1, different tape library, running on Windows 2008 R2.

My question is, how can I restore data from those old tapes? I'm being hounded by Legal :-)

Any help would be greatly appreciated.

Thanks.