Is there a way to switch Engineering Specs?

[espoir]

Anyone know if you can unlearn a specialization for engineering without having to unlearn ALL of engineering?

[Setup]

1) unlearn all engi

2) play a different version of wow

[espoir]

Well I know there is supposed to be a book at a gnome guy's house near Steamwheedle Port that you can read and the option is supposed to be in there to unlearn engineering specializations, but it doesn't seem to be implemented yet on the PVE server. Not sure at which point it becomes available.

[Bit]

Afaik you can't switch even if you unlearn engineering.