There are a few ways you could achieve this. The way I am doing it is through winSCP, but you will need to set up SFTP access first. There's a good walkthrough on the pre dev wiki. Just seach for it (can't post links yet, sorry). Then you can access your Pre just like a regular FTP client, you can browse the folders and open the images by right-clicking and selecting 'open'.
This you want want to do it that way, the other option is to SSH in (through puTTY, etc.) and copy the files located /var/luna/data/browser/icons to your internal storage. The path to that is /media/internal, which is the root folder you will see when you connect your Pre as a USB drive.
So, for example, if I wanted to get an image from /var/luna/data/browser/icons and put it on the 'USB Drive', I would type as root:
Code:
cp /var/luna/data/browser/icons/image.png /media/internal
When you plug your Pre in as a USB Drive, the image will be right there. Then to copy it back, it would be the opposite.
Code:
cp /media/internal/image.png /var/luna/data/browser/icons/
I hope this makes sense, and I haven't been too confusing.