I hope you still have some hair left... :PI've played a little bit with iClone 3.x and it's not straightforward, but there is something you could try. It should work the same in IC 4. Note that you can not animate this but you can make the head disappear. Before you do anything, you should probably save a copy of your character so that you will still have the original.
I assume you have a graphics editor associated with iClone; you can do that in Settings. If you don't have one, try Paint.NET; it's free, simple, and will do the job.
The teeth, throat, and mouth all have a texture associated with them. You will see that when you click the Mouth tab and then each of the radio buttons Teeth, Throat, and Tongue. The Teeth has an Opacity map patterned after the teeth. Click Lauch; the Opacity map will be opened in your graphics editor. Make the map completely black, save it, and click Update. This will get rid of the teeth.
There is no Opacity map for the tongue and the throat. Create one, which can be a simple square graphic (256x256, for example) that is completely black. Double click the Opacity icon for throat and tongue and load the black graphic. This will take care of that.
The same procedure can be used to get rid of the eyes (separate for left and right). You will also need to set the values of Glossiness and Specular to "0", otherwise a glow will remain.
The head is easier as it has an Opacity slider, but again Glossiness and Specular need to be set to "0", otherwise a glow remains.
A choker is a mystery. You could save the clothes and boots and put them on another girl. If you need the head for some reason, you could save that separately and put it on the same girl.
Here is a headless Camilla in an appropriate environment. I think the choker looks kind of cute... ;)
