I just took delivery of an old non s & s Heng Long Tiger today, I need to take the top off to see what the damage is like inside (turret rotation is dodgy, no airsoft gun operation, that's just what I know of so far). I found three screws underneath which I unscrewed but nothing seems to have become free - is there a knack to getting the top off? Am I missing something?

UPDATE: Oh, not to worry - I discovered a guide elsewhere for disassembling the Tiger.