Switching Engineering Specialisations

Preword: Sorry if this is the wrong thread, if a kind moderator would kindly move it to the appropriate location if it is in the wrong location that'd be ace, this just seemed the best fit to me, a guy who hasn't spent any time on the forums to date. Sorry and thank you in advance.


Subject: Switching Engineering Sub-specialisiation from Goblin to Gnomish (or indeed, the opposite):

To my knowledge, changing the professions requires using the book: "Soothsaying for Dummies" in Tanaris above Steemwheedle Port. This I successfully did to remove my existing Goblin specialisation (at the cost 150g), in order to take the Gnomish specialisation. I have (I believe) done the "show your work" quest that is required for that goblin engineering access.
What I haven't done (because I was able to use the aforementioned book I believed it might be possible on warmane without nuking the entire progress I have in the profession to merely switch specialisations) is remove the profession by deleting it, in order to start over (to my knowledge, required step on blizzard servers): So what I wanted to ask before I go ahead and do that is... (tl:dr)

"Must I delete engineering in order to switch specialisations on Warmane?"

In other professions such as alchemy, you can switch without dropping the profession entirely, so I didn't know whether or not a quality of life upgrade would've happened at some point in the past on the server to be considerate of those who found themselves needing to make the change.

I have checked the alliance (I am alliance, so can't check for horde) quest givers for the "Pledge of Secrecy" quest and all available prequests with no luck for switching or restarting a specialisation, whether goblin or gnomish, so I guess my question is... what do I need to next? If I drop the profession entirely will I be able to choose a new specialisation? Will I lose all my trained recipes or will I get those back?

Many thanks to anyone who knows the situation and can fill me in on the details!

Peace

You use the book to unlearn and relearn specializations.
Unlearning a profession will do just that, unlearn all profession recipes (spells).