If you lift up the rear sight plate (the part with the numbers written on it) look towards the front where the plate hinges. Underneath is a springy piece of metal. Take flathead screwdriver, and put some electrical tape on the head so you don't scratch up the finish. Take a rag and wrap it around the handle of the screwdriver. Push down on the metal below the front sight with all your body weight. I straddled my unloaded Tantal and pushed down, to give you an idea of how much force is required. The rear sight plate should be pretty easy to get out once you see how it's actually held in. It rides on two grooves on either side. One you pull the sight out, it should be pretty easy to figure out what to do. Take the sliding barrel off and put it back right-side up. Reinstall everything just as you removed it. It took me 2 minutes to fix, and as you can tell by this tutorial I don't know my AK-parts and terminology very well.