Have to say what a pig of a job removing the tank and reinstalling was, trust me to pick the hottest day of the year didn’t help.. A few things that might help out others.....
Those small black plastic fasteners are released by depressing the central section, and when reinstalling pull the mid section down, insert, and then depress the central sanction until it clicks.
However the biggest cause of angst were the two retaining bolts holding the tuppware down, Jesus H Christ they were a friggin nightmare (see pic). They screw into a bendy’ish metal support , get one side in the other ain’t going.
How I did it.
Stuffed a clean microfibre rag under one side to support it, go to other side get it started don't tighten, return to the side supported by rag eventually I got it started, pull the microfibre out.
Not sure if anybody else has suffered this issue, anyway it worked for me.
All done, and the spots work just fine but took me longer than anticipated.