He can buy the amiga explorer and transfer files trough null cable also 
But the easiet way is what I wrote above, just boot your Amiga harddrive in UAE and put TSGUI on it and the adf files you want then just run TSGUI on your real amiga and put the ADF files to disks
Easy as pie!
Accessing an old SCSI drive in UAE on a modern PC isn't exactly easy, especially if you don't have a SCSI card for your PC lying around (I'd bet most people don't.)
As for Amiga Explorer, why pay for something you can do for free? Though Amiga Explorer would probably be alot simpler for most than getting an old SCSI drive running in a PC, or transferring files with ZModem.
