Very difficult to recover their files. The fine details of how data are managed in a RAID0 array vary depending on which RAID system did the managing. The normal result is that plugging two drives full of data from an old array into a new system managed by a different chipset and / or RAID software means the new system cannot understand the old data. The straightforward option is to reconnect those two drives in a machine with the SAME RAID system as they were written on. But you say that machine is gone and dead, so that's difficult unless you can find another machine like it and use it temporarily.
There may be software you can get that can figure out the old RAID system organization and allow you to read the files off and copy them to a new system. I don't know of any, but I'm sure I have heard of such a tool. You could search the web for such software or, if you're lucky, someone who has used some will come here and tell you details. In the meantime, don't do anything with those disks. Wait until some solution presents itself.