1. long press on facebook.db until the options menus

2. select copy, the paste and cancel buttons should now appear at the bottom of the screen

3. press the parent folder button at the top of the windows until you are back in the root folder, it should now say mounted as r/o with a button to mount r/w at the top of the window

4. Scroll down to "sdcard" and click on it

5. Hit the paste button at the bottom of the screen, the file should now be on your SD Card​