The UVW Map is a great way to know exactly what is what inside the texture, and it also gives you great guidelines to work with. Ill be explaining in this section how to export the models UVW Map and put it into Photoshop to work with.
So first we select our model in 3DS, go to the Modify tab and select "Unwrap UVW", once we have it we click on the "Open UV Editor" button under the "-Edit UVs" tab. This will bring up the UVW Map window, go to Tools>Render UVW Template. Enter the width and height you used previously while re-sizing your texture (either 512x512 or 1024x1024) and press the Render UV Template button. Then click on the Save icon and save it as a .PNG:
Once we have the UVW Map saved as a .PNG, we open it up in Photoshop, drag over our texture into the .PNG file, make sure the texture is placed correctly and keep the UVW Map's layer above the textures layer, it should look like this:
Now we successfully have the UVW Map in Photoshop, ready to re-texture the armor! The great thing about the UVW Map, and mainly why we put the texture into 3DS is that we can use 3DS to identify what parts of the texture go where on the model, for example:
In that example we re-opened the UV Editor window and using the Polygon (or Face) tool selected a random piece of armor. Normally we would not really know what it did without extensive trial and error, but by using 3DS we discovered that it was the tip and side of the shoe.