Scan is on by default if you have the Fiery, just scan with any of the 3 templates (COLOR0GUEST, GREYSCALE0GUEST, BW0GUEST) and then open Fiery webtools in a web browser (Put the Fiery IP in a browser address bar) and retrieve the scans from the DOCS tab
To actually send to your PC in a folder, you need to have SMB or FTP setup on the PC and a username and password the Fiery can use to access the folder remotely. Once that is setup, you simply create a template on the Scan Settings tab (You need to be an admin to create one)
Then give it a name (All caps, no spaces), put guest as the username (case sensitive) then fill in your own relevant FTP or SMB info to your PC with the required username/password as set on your PC.
Troubleshooting will be tedious, the Fiery has no way to tell the printer that the scan failed, so if it doesn't work, you will go no hints as to why.