We have a dual flush toilet, circa 2010. Caroma Flinders/Venecia. It has blue and yellow plastic on the top where the flush button pushes on. 

What happened is that pressed flush button and it went free, so googling tells me the mechanism that connects the push down on the flush valve to the flapper has come adrift. Given the lockdown I thought Id remove the flush valve in case its an easy fix. But concerned that I dont break it. It appears from googling Caroma that I can turn it a bit left to unclip, then lift out. But then I saw there are quite a few models, so didn't want to break it

Any ideas?