Dumb question but switching private reg to new car

[walm]

Google is leaving me a little confused, sorry!

I have a private reg (came with my current car).
I am buying a new (to me) car.

I want to put the private reg on the new (to me) car.

What I don't understand is how this actually works in practical steps:

I drive old car to dealer.
At the dealer apply to DVLA online to transfer plates.
Get a code?
Leave plates on old car or do I take them?
Use above code to apply to new car?
Put plates on new car?
Drive away?

Is there some sort of time lag between applying to transfer the plate and actually doing it?
Do I need to leave the old plates and just print new ones when the transfer is approved?

Thanks.

[rewc]

This can be all be done on line and the system works.

Put old car on a new age related number allocated by the system. Do this asap.
Put number on a retention certificate.

Pick up new car on its existing number.
Put new car on retained number.{ It is possible to put it on prior to picking it up if you wish.

See How to transfer a registration number in the link;
https://www.gov.uk/personalised-vehicle-registrati...

[walm]

Perfect - thanks so much rewc.