To pull the battery out I used my spunger, but the batter had actually not space to be pulled out completely. I needed to lift the cable up with the spunger to get the cable fully out. When plugging it in again I had to press the battery down kinda hard so it would fit again. This was really scary and I recommand using two spunger as someone said above.

This step was the hardest by far. First I didn't find an opening at the sides, and it did take a really long time until I finally got it open... Then, when I had the one side opening open it didn't just pop out, I needed to slide all the way to the other side with the pick and open everything. I guess they made it even more drop resistant.