Allright, so I'm finally done. It was a little more work then I expected but that's what you get when you are an optimist. I changed the battery in my own garage and in hindsight I wish I had invested in better, taller jack stands. The car needs about 70 cm ground clearance, at least if you are going to take out the battery from the back of the car.
After the car had the proper height it was actually not to difficult getting the battery out. I used a lifting table on wheels that I borrowed from a friend. ( Minimum height of table was 34 cm, battery pack is about 26 cm. And some extra cm penalty for taking the battery out from the back of the car) .Then it's easy to support the battery as you unscrew the bolts. Of course, you need to unload the old battery and get the new one on the table - there is some logistic there that took some time as well.
Another issue I had that took a long time figuring out was how to remove the main battery cable. Nissan has made some crazy patent that involves first pressing really hard on one side of the cable-release-mechanism , pull a little and then press another place. Why?
Swapping out the VCM was one of the easier parts of the operation. You just have to remove all the screws you can find on the inside and outside of the glove department and take the hole thing out. Than it's straight forward.
After swapping the battery and the VCM I of course wanted to test the car only to find out I got a lot of error messages. It all boiled down to that the keys need to be registered in the VCM. It's a straight forward procedure that has to do with Nissan immobilizer system. I got no error regarding incorrect battery ID or anything in that regards ( Leaf Spy pro). The range and everything was displaying correctly but it was not possible to get the car out of Park. This is where my part of the job ended. I had to tow the car ( front wheels were locked so I just called the professionals) to Nissan and they actually were quite helpful. They registered the keys with the VCM and now everything is working properly except the app. I'm not able to preheat the car or read out the battery information using the Nissan app. Interestingly, I can see my driving history on the app.
2014 Nissan LEAF Tekna 30 kWh