Hi, my third brake light has gone out, also known as the high level brake light on my 5 door Astra J (2012).

I have read the forum and the following link, https://www.vxoc.org.uk/forum/Thread-Hig...rake+light. But there isn't a walk-through on how to actually remove this. I've googled it and know where can I find a walk-through on how to do this this looks really difficult as mentioned by people on here and other forums. I would really appreciate it if someone