DPMS Full Auto SBR - How to open magazine - No tools or fingernails

I just got this and was struggling to open the door to the mag. The instructions said to insert your fingernail and push up in the direction of the arrow but it wasn't opening and the plastic was creaking like it might break so I went to youtube for a solution and literally no one seems to show how to actually open it. But I eventually figured it out and without any tools or fingernails. Just place the your thumb over that hole and then your fingers on the seam (on the side the arrow points to) and rock your hand as I show in the video. Let me know if that works for you!

[@chord972]

Thank you.