Copied this over from the archives. Credit to Anzu, Shivadas, and Caligari for this post.
Go to ..Funcom\Age of Conan\Data\Gui\Default\Views\HUD\BottomBar.xml
Copy it to ..\Customized\Views\HUD\BottomBar.xml (You'll need to create folders if you don't already have them)
Open the new xml file in your customized folder and find:
<BitmapView name="ExtraBar" (~line 84)
Delete the word "ExtraBar."
Save and reload your game.
*note, you wont actually get the lower left and right attack abilities, but you'll have 3 more slots that default bind to Q, V, and E. A handy trick for non-custom UI users.
(this part is only required if you CHANGED "ExtraBar" rather than deleting it)
If you want the little graphic borders around the top buttons after the Q,V,E buttons are exposed then use the same approach on the following lines to force them to show along with the extra slots:
(~ line 31) Change <BitmapView name="OrnamentLeft" to <BitmapView name="OrnamentLeft_FuBar" or whatever you want.
(~ line 96) Change <BitmapView name="OrnamentRight" to <BitmapView name="OrnamentRight_FuBar" or whatever you want.
Note that from time to time you may need to change the custom file's version number to match the official file number when it is updated.