Bose QC35 - disassembly

So I have a pair of QC 35 since a couple of months, I bought them brand new from a particular.

Since a few weeks I'm facing a problem, the inner ring of the left speaker makes plastic cracks that are incredible audible when turning my head in any direction. The exact place where the noise pops is the physical connection between the inner ear and the speaker itself, somehow it seems like it is scratching with something. Blowing or puring a drop of a liquid inside it seems to reduce the issue for a very short period of time so I decided to disassembly them for good.

The thing is, I don't seem to find any guide on how to do it, most of the guides just open the speaker, replace a part or two and that's it, but I need to remove the speaker from the ring that holds it. Anyone knows how to do so?