Identify toilet cistern

[Jillmc]

I need to replace the washer on the toilet cistern in my bathroom but cannot work out how to get the lid off of the cistern.

It is a dual flush cistern and when I try to lift the lid up it is very tight. I can lift the flush levers out of the lid by about 2 inches but cannot find the release mechanism.

The only identification I have is on a sticker on the side of the cistern that says AS1172:2 LC1617 Australian standard.


nb I am a novice DIYer

Any help would be appreciated.

 

[HERTS P&D]

Post a pic of the cistern lid.

The buttons should come up to reveal a screw or the button should unscrew.

Andy