You Can Edit the image Channels from Channels Panel Window> Channels and it will be more easy if you change the color mode to CMYK from Image> mode.
You can also use the adjustment layers from Image> Adjustment .... it will give you a mask to adjust exact area and leave another.
I would try Curves or Selective Color for that area. Match the dark grey background and the rest of it should come close.
thank you for your feedback. Can you be a little more specific on how to use selective color? thanks, yvonne
thank you for your feed back. How would I use the channels to get rid of this stain? thanks for your time, yvonne
You can also used a brush set to color... There are a ton of ways to tackle this.
Perspective Crop will square up the image
Content Aware Fill will get rid of the stain in the background
The faces require individual correction but the print is badly bleached, stained and splotchy so there is little to recover.
Woman's face needs more time than I devoted to it.
I overdid the sharpening.
Under pressure to do some chores.
Can you please be a little more specific? thanks
Can you add more detail as to how to use Content Aware Fill?
Regarding Content Aware Fill:
Use the Quick Selection tool to make a Selection of the background.
Cmd+J to put it on a separate Layer
Lock the transparent part of the layer for insurance (it is the symbol adjacent to the word Lock)
Use the Lasso tool to select the stained areas.
Choose Edit > Fill ... Content Aware (Next to the word Contents)
The reason the background is placed on a separate layer its to keep Photoshop from referencing the people as it calculated the fill content.