This heavy duty drawer slide is from a kitchen cabinet and I can't figure out how to release it from the cupboard. I tried taking off the bottom screws, but it still won't come off. There must be a release mechanism, but I can't seem to find it.
Turns out all you need to do is lift the drawer up when it's at full extension. It takes a bit of force. To put it back in, you just slide it in. Here's a video I found:
Those appear to be IKEA drawers, there is little tab that must be pressed while pulling the drawer out. It is a little white tab, you can see it in a slot cut into the metal of the slide just a little in back of the grey plastic piece. You need to push up in it with a small screwdriver or anything small enough to fit in the slot.
A video will do better at explaining this.
Here is a video that explains the adjustment screws you see in your photos, they adjust the drawer fronts.