well you could use a flat head, but a small phillips screwdriver would fit too, and it is near the SL1 contacts that are use to flash the firmware.
here is a crude pic of where I am talking about, sorry bout it being blurry, I used a youtube video showing how to change the battery.
here is a crude pic of where I am talking about, sorry bout it being blurry, I used a youtube video showing how to change the battery.








