I would like to change some of my specializations around to make the Ironworks gear. I am wondering how this works exactly.

I have bought one Soul of the Crafter with Red scrips. This is a unique item right?

So that means I can only change my specialization once every week (if I already have one Soul of the Crafter in my inventory) or two weeks (because one Soul of the Crafter costs 480 red scrips).

So if I wanted to change my specialization three times it would take several weeks. Is this a correct assumption?

And I would need to buy another Soul of the Crafter to change it back?

If it is as complicated as it seems, it seems like I should ask someone else to make some of the gear for me.

Do I need to speak to an NPC to change it, or can I do it myself? How exactly does it work?

Could someone with experience doing this please explain it to me?

Thank you in advance.