You take the main body of the NRG, that image with the shape of the well.. main skinning part. Copy that name and keep it for a second. Then go into PS or paint and make a grey background. The darker the grey is, the more transparent it becomes. Now save it as the name you copied + and extra "a". So "NRGbody" becomes "NRGbodya". Use the same resolution as the body aswell.
Now go to Txdworkshop and add an alpha layer to the NRG body. Import your NRGbodya image to it and save the NRG. This is how it goes in VC, don't really know about SA but give it a shot.