Now you should have something that looks like the image below, on your right hand side of user interface.
Step 10 :
Ok, expand the Paint Attributes tab and then in the drop down menu, my default for Paint Attributes it set to Density so leave it like this. Now expand Attributes Maps and you will see one more tab called Import. Expand this too as this will reveal the Import button. Click on it and the file browser window will open. Choose your density.tga from where ever you saved it to and import it, like the image below shows.
Step 11 :
Press the 6 button on your keyboard and you should see something like the image.