Just pull it off....it is fairly fragile...lucky for us that it is a simple single-throw normally-open type switch, so its absence doesn't have any real impact as long as the unit is plugged in when you change the battery out. If it were the other way around, normally-closed...then we would have to solder a bridge between the contacts or else get the error you see about the battery being unlocked...
The switch redirects the main current flow, preventing the coin batteries for discharging and providing power to the circuit board when the battery is absent.
In other words, without the switch, and with the unit unplugged, if you remove the battery, you very quickly deplete the coin batteries as the device pulls current from the backup batteries as if they were the main batteries. Give it a try if you want to waste a good CR2032 in less than a minute!
With the switch operational, the backup batteries will only supply current to maintain the RAM state when the main battery is removed, regardless of whether the 900 is plugged in or not. Even that will only last a short while
(about an hour
) however without the a/c supply or main battery in place.
Anyways, a good pair of needlenose pliers will pull it off.