Could you tell me which difficulties are you experiencing? Here are some suggestions for you:
1. Just plug the C3 into a computer and choose "Ovi suite". If you're running Windows 7 or 10, chances are that the C3 will show up under My Computer as a music player. Just double click on the icon and copy the photos over to the PC.
2. If the photos are on a Micro SD card: Connect the C3 with a computer but choose "Mass storage" instead. The C3's memory card will show up as a regular USB device in My Computer.
3. If the phone is not recognised by the computer, your best bet is to copy/move all photos to a Micro SD card, then put the card into your new phone. Alternatively, you can use a card reader to coppy the photos to a computer.