Working Holiday Visa to Engineer visa UK

I managed to secure a job just before activating my working holiday visa. They are going through the COE process now. I know I can't change my status within the country as a UK WHV restriction.

I'm a little confused about how I swap from my current visa onto the work visa without having to terminate my residency, hand in my zairyu card, close bank accounts etc.

Should I reenter on the WHV? And try to sort this at immigration?

I could leave and hand in my zairyu card and return to trigger the work visa on the same day too.

by seoceojoe