Removing Price Pfister Tub Spout

[sp0811]

I need to replace an older style (sorry, don't know the model) Price Pfister tub downspout/diverter. There does not appear to be a set screw, even though there is a slot on the bottom of the spout where I would expect to see one. Any ideas?

Thanks.

[Terry]

If there is not set screw, then it would unthread off.