Select the area you would like to X-Ray There are two easy ways of doing this.
1. Magnetic Lasso
or
2. Magic Wand Tool
If You choose the Magnetic Lasso Tool, Set the width, (1-5) Edge Contrast (75-95) Frequency (50-75)
It is easier to go around the pic if you can see the whole selection, so set you zoom enough where you can see the
entier garment you will select. Pick your starting point and keep a steady hand and go around the selection.
After going aroung image, click the box you are connecting to, to make the selection. After Selecting, right click inside image,
and select "Fether...", (3-5) . Move the mouse to the main menu tool bar and select the "Layer" Pulldown. Select New ,Layer,
click ok.Look at your Layer Window, select the eye on Layer 1, then click on Background.
If you choose Magic Wand Tool, Set the Tolerance (5 - 20)
Hold the shift key down and click your wand in the area you would like to select. If you wand is selecting areas that you dont want, then try to turn down the tolerance. After makeing you selection, right click, select "Feather.." (3-5) Move the mouse to the main menu tool bar and select the "Layer" Pulldown. Select New ,Layer, click ok.Look at your Layer Window, select the eye on Layer 1, then click on Background.

After making you selection, the rest is up to you. I can tell you the things you can do,
but everyone has a different eye for this.

Setting Brightness/Contrast
Brightness 10
Contrast 25

Color Balance
Shadows Midtones Highlights
Cyan -49 +17 +23
Magenta -45 -25 +30
Yellow -15 -52 +39

Hue/Saturation
Hue -4
Saturation -8
Lightness -9

The only thing really left is dodge and burn, but use wisely
Thats pretty basic X Ray. Once you start to practice, and learn the tricks of the program, you can create some awesome pics.