Sorry guys I do not have a microphone so there is no sound
If you haven't set up Blender go and watch this Video from JaoSming first.
Blender Proper Installation & Plugins - http://www.youtube.com/watch?v=nlX5y_yVuaI
Tools used
Blender
http://www.blender.org/
NBA2KX Mod Tool (2K12 Supported)
3DM Mod Tool
Photoshop
http://www.adobe.com/products/photoshop.html
or Gimp works as well
http://www.gimp.org/
Some Blender scripts, you will notice I use one of them a few times in the video for mass renaming.
http://download.blender.org/release/Blender2.49b/
You want this one "blender-2.49b-script_bundle.zip"
Tip
You do not need to convert the headband "IF" you do this step instead.
The 2K13 headband has 145 vertex and the 2K11 has 144 vertex. The trick is to add one extra vertex to the 2K11 headband and it will import fine and work without problems as far as I have tested.
In the picture below is where I add the vertex, just above the left ear (bottom of the headband) Select the single vertex you want to duplicate and Hit Shift+D on the keyboard. Important, Do not move your mouse after Shift+D before you left click the mouse once to set the position. After you hit Shift+D it will place the vertex but it will move with the mouse unless you set it. I hope this is more clear than mud