I realise this is an old posting, but just in case anyone is reading and wondering, these still being available from Amazon etc, this is the info on how to change the DVP3120 for multi region use.
1. Turn on the unit
2. Open the loading tray
3. Press the "Setup" button on the remote
4. Navigate to the "Preferences" page using the right arrow key
5. Enter 138931
6. You will now see the current region code displayed
7. Use the Up/Down arrow keys to select the region required or "0" for all regions
8. Press the "Play" button on the remote to store.
Another little pointer is that there is no "open or close" button on the remote control, this being achieved by holding down the stop button for about a second and the tray will open.