I changed one leg of my flight from CW to First. How long does it take to reissue the e-ticket? I was told it goes into a queue and done on flight order.

Whilst I'm not flying for some time, last time I modified a flight by phone it took ages, then someone decided I couldn't do what I was doing, and tried to cancel the whole lot, so I'd be happier once it's ticketed.

TIA.