In the Editor, there is a panel in the Meshes tab labeled Mesh Scale. The features used in this panel have been built specifically for use with Avatar Head products. So, if you want access to this panel, you need to Derive from a Head product.
Open Create Mode, click the Derive a new product button and choose to Derive from a Head product. For the purposes of this tutorial, choose to Derive from product 59412.
When the Editor opens, click to expand the Mesch Scale panel. If you have Derived from 59412, then you will see that the Mesh Scale Parameters have already been turned on and tweaked.
Since the Mesh Scale feature was built to work specifically with Avatar Heads, you are meant to type Head into the Node Name text field.
You can type different integers into the Scale X, Y and Z text fields. Then, hit Apply Changes and see how your inputs affect the head.
scales the head's width.
Y scales the head's depth.
Z scales the head's height.
You don't have to use the same numbers in all three input fields. For example, you can have both X and Y be .85 and then push Z up to 2.0. Then, you'll have a really tall Head. It is in this way that you can adjust the dimensions of a Head to fit your aesthetic tastes.
Make sure you hit the Apply Changes button when editing the Mesh Scale fields. Otherwise, you won't be able to see what effect your changes have on the Mesh.
Now you know how to Scale an Avatar Head using Mesh Scale in the Editor. Just Save your file, create a screenshot and submit to show your creation to the world.