Consolidate Unifi sites

I manage a bunch of Unifi sites (different companies)
Each has a controller at that location

I want to bring them all in-house and manage them over our VPN

Last time I tried to do this, the remote AP device got hung up during adoption and repeatedly rebooted. Had to get the client hard-reset the device - I then just configured re-adopted it locally

What is the best process for for integrating remotes sites into 1 site ?
ie - Do I have to ssh and point it to the new controller - Do I need a DNS entry of some sort ?
Is there a definitive how-to on this ?

Thanks

Steve

Using the site migration tool

But per this post, don’t do it using the new UI

Thanks - that link was perfect

Steve