Must be AGM due to the stop start and of the same AMPS etc, if you can afford it replace it with the same AGM Varta already in the car or the equivalent AGM Bosch like the one I have. Disconnect negative 1st when removing.
Then when installing connect the negative 1st.
Just loosen the 1 bolt on each of the terminals enough to allow you to easily remove the cables.
Make sure everything is turned off in the car before you do anything fans , radio , remove key from ignition etc. It will avoid any voltage spikes as you replace the battery.
Once you remove the terminals from the battery push them out of they way and cover them with a cloth just in case they fall back to the terminals of the battery when you are working.
yes there should be a bolt by that side of the battery with a plate that comes out if I remember correctly. Once the bolt is loose remove it by hand if you can and vice versa as you don't want it falling in to the engine bay and being stuck on top of the under tray.
VERY important...... Make sure you got yourself in a good position to move the battery out and over the fender of the car and also the new one in. They are very heavy and not the easiest. Ensure the battery cables haven't fallen back in to the empty battery box before you move the new battery back in to the car.
it happen to me and I had to move the battery back out to push the cables out of the way before lifting it over the side and in to the car again.
Once you have replaced it, run the car and your sunroof should work no problems and after a few miles of charging you stop start should go green and work again 👍😁.
i forgot to mention.... you can see an overflow tube on the side of the battery. carefully remove it from the side of your old battery before you take it out of the car and push aside.
Before you put the new battery in ensure that the hole on the other side of new battery facing the firewall has a plug.
I think both sides are plugged if I am correct on the new battery but check.
Once you have the battery in the tray of the car , bolted down and before connecting the terminals remove the side plug of the battery next to the tube and connect the tube to it just like it was in the old battery.
And that's it 👍