On your old computer go to the library and then press explore. The folder containing the files will open. Then burn/use memorysticks or whatever to transfer from that location to your new computer.

On your new computer. If you are using the default share folder then just put the files from the old computer in there just drag and drop from the CD/DVD or memorystick into the shared folder.

In case that the files are in red writing in the library highlight them, then right click and choose "Share this file"