1976 cb500t, how do you take the needle of the carb?

[V1nce Fox]

Asking for a friend. We had the needle and slider out on the bench and unscrewed a screw in the side of the slider (kind of like a gudgeon pin) but the needle still doesn't want to come out.

The other side of the slider has a hollow chrome barrel centred above where the needle base is, which is clearly not part of the slider itself (aluminium) and inside this chrome barrel there is no obvious sign of how to detach the needle.

Anyone got any input on this please? It's a Keihlin original carb.

[Turn7]

Any pics ?

[archie456]

There's some info here, looks like with the screw removed it should come out.