I needed to get access to the files on my PFSense box today to make a few changes. To do this, I used WinSCP, available here.
Once installed you need to make sure that you have enabled the secure shell on the PFSense box.
When that is done, open up WinSCP and enter the IP of the PFSense box and the login with ‘root’ and the webgui admin password.
Once in, you can then have a browse around and make any necessary changes.