Glock 17, chamber won't release - what can I do?

Pull slide all the way to the rear, allow slide to ride forward till it stops and allow pistol to remain c o c k e d,(stupid yahoo censoring) do not pull the trigger. Now while depressing the 2 take down tabs, slightly move the slide to the rear until you feel the take down tabs click, move, or bump, allow slide to ride back forward until it stop, now apply slight pressure on the slide to move it forward an off the rails as you pull the trigger. Sometimes those take down tabs will get a little sticky and really hard to move, I have found by moving the slide to the rear a bit it takes "pressure" off the tabs and allows them to be pushed down for slide removal. If this doesn't work, take it to any Glock qualified gunsmith, it's probably something very simple, like a bit of grit or br or shooting debris preventing the take down tabs from being pushed down.