Changing EVs registered Ohme & IOG

Hi all.

My Mum has recently changed her EV. I’m just wondering how we go about removing the old EV linked to the tariff and charge and adding the new one? Do we start the process on the Ohme app or Octopus app? I just don’t want to get anything wrong and mess it up!

Also, the Octopus app is still showing “Charge cap is coming soon”. So does that mean the 6hr limit doesn’t apply to our account yet?