How to replace AC vents on Octavia MkIII

Hi All,

I own a 2014 Skoda Octavia and the AC vents on my car seems to be especially fragile. Over time, all the AC vents i.e., both front and rear have fallen apart and now are borderline unusable. I found some replacement AC vents via AliExpress and am trying to find ways to replace them myself. 

I tried looking around for any DIY guides but am unable to find any. 

Has anyone replaced their AC vents and can guide me on how to replace them?

Thanks a lot.

Praveen