After install the Workbench manually, return the disk set to the seller and ask for another set with no faulty disks.
Without the serial.device (who is in the extras disk) and the cross-DOS (diddle), you can't transfer anything to another kind of computer.
But, if you have another Amiga around, use it to transfer files in the worst way: A-explorer, pc-floppies or whatever to the another Amiga (RAM: or HD), then format a real Amiga floppy to transfer the files to your 3000.
Yes, it's a pain in the back, but works.
