How do I clean the sensor?

I have a dark spot in bottom left corner of every picture I take (it’s not the screen I did check that by uploading the photos to my mobile phone) and was now thinking about trying to disassemble the camera and cleaning the sensor. Sadly I wasn’t able to find a detailed disassembly online and can only partly imagine how I can approach this repair without 1. destroying the camera and 2. how to move on after removing the display. Any advice or explanation on how to take it further apart will be appreciated.

Thanks in advance!