This skin is very simple and only does one thing - it hides the Auto Skill Bar. I've seen a few other people ask for the ability to hide the bar but have no other need for a custom skin so that's all this one does.
To install this skin, unzip the downloaded file to your "The Lord of the Rings Online\ui\skins" folder (you may have to create the ui and skins folders if you don't already have one), and then select in your Options Panel - UI Settings the NoAutoSkillBarSkin. Note that you have to unzip the folder before starting the game (or it won't see the new skin) and you have to restart the game after selecting the skin in order for the feature to take affect.
If you'd like to add this to your own skin, it's pretty straightforward. Open up the SkinDefinition file of the skin you want to add this feature to (you'll have to right click on it and click "Edit" otherwise it'll most likely open up in IE), and then just copy and paste the following into it:
<!-- Will Hide the Auto Skill Bar -->
<Element ID="Gameplay_AutoSkillBar" X="1" Y="1" Width="1" Height="1"></Element>
Many thanks to moebius92 for figuring out the PanelFile ID so this can work. Any questions, please let me know.