Hatfield 410

So I just bought my son his first shotgun, and I went with this single shot 410 by hatfield. Cheap shotgun, but I figured it would be a good starter. I cannot get the dang thing to open. Should pull back on the trigger guard and open it, bit it will not budge. Anyone have any experience with this?

button on front of trigger guard.

Watched that video, but it would not release. I took a screwdriver to it and loosened the screw behind the trigger guard. Finally did the trick. Hope it doesn't fall out.

might consider blue loctite on the screw set at the depth you want it