I wanted to keep this somewhat stock looking on the outside. So I re-wired the original switch to work with the Pi Sugar. The UPS wants a DPST switch so some modifications were needed.

I used a couple the no longer needed LCD pins since they already go to the flex cable.

I removed the original switch off the Pi Sugar and used the pads to facilitate wiring in a new switch. Since the connectors float when not connected, I added a second override switch on the perfboard. It's over on the left next to the connector. This allows me to keep the UPS turned off without the top connected.