Removing forend (lower hand guard). The lever has been rotated and the retaining piece moved forward. The front of the forend (shown) may now be rotated downward away from the barrel, and the rear of the wood removed from the receiver.
Locate the lever at the front right of the lower handguard/forend. Flip this lever upward and rotate it 180 degrees, and then slide the steel piece forward along the barrel. You can now rotate the forend downward at its front and pull it forward to remove it from the front of the receiver.
Index: Field-Stripping an AK-47 Rifle (and Variants)