It might not be as easy as you think if the system has somehow survived without an upgrade for decades. Who knows, maybe it's that ancient?

Back in the day I worked on CODASYL style databases (IDMS) that was EBCDIC. This is before relational databases were a thing. We had no PCs: all of the companies’ data was is in the Mainframe in EBCDIC. No ASCII anywhere, let alone UTF-8.