http://bentasker.i2p/posts/documentation/shooting/smk-xs26-stripdown.html?utm_source=rss
There's a screw on either side of the gun, remove both: There's also a screw on the underside: Keeping the gun upside down, grip the barrel with one hand and carefully pull the stock up and away. Just behind the trigger, there should be a small plastic pin, backed by a spring. The pin is loose, so if it's not there, it's either still in the stock or has fallen out onto your workbench.