It's going to be far easier to copy the whole of both fids directories to the new drive than anything else. Yeah, it'll take a while for the music to be copied, but you'd have to upload that music anyway.

The fastest way would be to hook the drives up to a Linux computer and copy the files on it, since you'll get better IDE performance with a real desktop than with the empeg.

But if you want to do it all in the empeg, take both drives out and install the new drive. Load the firmware onto the new drive. Reattach one of the old drives as a slave drive. Copy all of the fids directory from the old drive to the new drive. Take that old drive out and put the other old drive in. Copy all of its fids to the new drive. Take that drive out. Sync with emplode.