I rummaged into my connectors box, and found nothing that could help. Then, eurêka! I had an illumination...
Step 1: You will need...
- two rows of a double row .100" regular "snap-off" headers
Step 2: Slide it gently but firmly
Be careful with your fingers, these terminals can and will break your skin if you push hard enough!
Step 3: And voila!
When using a breadboard, make sure your are not shorting the battery (the battery should be parallel to the contact lines).
On another line of thoughts, I added a small 1uF capacitor in parallel with the backup battery connectors on the chip (not pictured). It gives you enough time to change the battery without losing the time.