VPCJ12M0E (desktop) noisy/rattling fan

[Burdon2]

My VPCJ12M0E all in one desktop has developed what I think is a noisy fan. I would like to clean it/replace it but cannot understand how to get access. The noise - sometimes a rattle - seems to come from the left hand side (if viewed from the back) and can happen when the storage disk appears not be being read. All UTubes etc seem to be for VAIO laptops. Any pointers please? 

[Blencogo]

I know it is not exactly the same model but does this help?

https://www.youtube.com/watch?v=HYk377YZeyY

https://www.youtube.com/watch?v=NZY27zuiySM

https://www.youtube.com/watch?v=3vdAMn12540

https://www.youtube.com/watch?v=fiymV8zEsXY

https://www.youtube.com/watch?v=ZriC2J0KI6E