> so do all 4 characters in the town get stuck with the same 2 hdlc?
Yes, they are a global setting. It doesn't matter what is in pockets or in catalog bits. That's why the DimentioMsk HDLC item appears in Able's store sometimes.
See OHDLC discussion here: http://www.aibohack.com/wii/ohdlc.htm

As mentioned, non-hackers have the unrealistic option to restart their town (and then be sure to connect to your town first)
Teach your friend how to WiiBrew (assuming they have a PC and SD card reader, it isn't that hard). This will fix his immediate problem, and let him explore the other cool gamesave tools like ACToolkit, PattView and NPC_Tool.