ejecting battery

Hi I have an ST3 and I can not eject the battery
the battery is at zero charge and each time I start the st3 it request an update that fails after few minutes therefore I can not access the menu and can not eject the battery.
The charger has two lights (one is red and the other blinking green)
Is there any other way of ejecting the battery ? or how to cancel the update in order to access the main menu.

Regards