Hi Bill
glad it is ok...
PWL is painting with light.
It is my favourite action to work with. Provided by one of the very best retouchers here a guy called Chip Springer.
It is available thanks to Chip, free...at ATNcentral.com
Just have a look on the site and look for PWL...there are many actions there and you will ee how good they all are.
To get the effect I used a day to night technique from another of the great retouchers...Peano.
With that you put a new later above the subject, fill with black and reduce the opacity to see the image below...but keeping as a darker night-time image.
Then a new layer above set mode to vivid or hard light.
Then with a brush at about 20-30 opacity paint in lights with yellow/beige colour
Then I adjust the black layer to taste (opacity)
Then flatten.
Then I use the PWL to bring back some of the lightness etc....
I hope that makes some sense....if you have a problem, let me know and i will try and help Bill.
Suggest you have a look in retouching by doing a search for DTN (day to night) by Peano.
I am sure he has done a great tutorial.
Kind regards
Ray
... and I think everyone else has too. 
