I have a ceiling lamp (shown in attached picture) mounted in my bathroom. I want to remove the lid and change the light bulb inside and replace the lid. However, I am struggling to remove it. There are three black holders (clamps). One of them feels like a spring plugged in and has an arrow pointing outward. I tried pulling it out but it doesn’t release the grip on the lid. The other two black clamps don’t budge either. I tried rotating it, applying pressure to the center to life the glass a bit higher but nothing seems to work. Anybody have any ideas? I live in Germany and presumably this was purchased in Ikea but i can’t find the product in their website.