They're byte-for-byte images of 3.5" diskettes with a (typically) 64 byte header tacked on to them. You'd need to get them written back to a physical floppy either by:
- 1) Sending the 2img file to the IIgs via a telecomms package, then using a program called Asimov (
2) Having a program like ADTPro that directly transmits to and writes the disk on the IIgs (http://adtpro.sourceforge.net)