struggling with 2014 standard sat nav system

From memory back in 2021 when we put the final 2020 update on, you switch on the ignition and head unit, flick the little plastic tab down on the sd card (I think) then push into the sd card slot.

Then wait while it whirrs away copying files. I think it took a couple of hours so best to do it in a garage or where you can keep an eye on it with the key in the ignition. You don't need to worry about charging the car battery unless it's showing signs of being on its last legs !