dismantling bathroom cabinets

[WaterTight]

i've never assembled bathroom furniture, never done flat pack stuff, never fitted a kitchen, so go easy on the space age technobabble. after removing shelf, how would i take this back piece off:



i've forgotten what those fixings are called you turn to release the little wedge bit. i can feel in the next cupboard there isn't one on the side of the back piece. running my hand around i can't feel anything to undo anywhere.

i need to remove it to tee into pipes behind it and then run them to the left as shown here



then to run the feeds through the left panel, which will also need to be removed before that can be done.

this panel:



how do i remove this one? it's grouted rather than siliconed on left. but i'm guessing if i get some of the grout out the way it will pop off with a thin screwdriver? how best to remove grout the free it up? poss to do it without damaging it?

thanks

 

[WaterTight]

oh and excuse the blurred pictures. the camera on my phone has gone bonkeroony.

 

[mutley racers]

The hinges either screw off or have a little lever at the very back. The back panel will have little screws and dowels in which will be accessible after taking a side off and the grout...multitool