Brad Barber rebuilt his units and first reported the "how to" to the mail list. The below email is being reprinted with the author's permission.

"I went to Radio Sh*ck and bought a couple of molded plug patch cords. I opened  the Nady headsets up and desoldered the wires from the speaker and mouthpiece.

I then cut off one end of the RS patch cord and soldered them directly into the speaker and the mike connections. You must be careful; here as the attachments are very small. The ground is common for the mike and speaker, BTW.

Add some hot melt glue to the mike tubing where it meets the earpiece. this will keep it from rotating with use. I also attach the coax to the mike tube with a tiny ty-wrap to keep strain off the coax when the student pulls the unit out of their helmets by the wire. I also left extra length to one of the units so I can route the wire over the student's shoulder and away from their arms. The one for the instructor can be made a lot shorter."