WD 40 
the answer to many problems…
Always knew you were a groovy person
Did you butter the edge of the glass? 
Why would anyone want to interfere with fridge shelf arrangements?
I did oil the side of the glass shelf and the plastic protrusion… but what did l do next?
Drop it! :shock:
Please tell me another way of thoroughly cleaning them without taking the shelves out and cleansing them in a sink of very hot soapy water?
My mistake was putting the one shelf in the wrong place then trying to remove it but couldn’t!
Ermmm… No! 
Yes, WD 40 is brilliant but l didn’t spray it in the fridge this time… l’m too young to die!!
Did you slide the plastic protrusion off?
We do the best we can.
Lifted one side up
No it was a plain glass shelf with no plastic edging like the other two shelves.
When l refer to ‘protrusions’ and ‘grooves’, l am referring to the sides of the inside of the fridge where it is moulded to fit the shelves.
I couldn’t as it wouldn’t go over the moulded protrusion of the side of the fridge.
It’s how l tackled this protrusion to get the edge of the glass shelf over it, straighten it up and insert it into the side grooves.
Pushed the protrusion to one side, in the basis that the plastic panel is flexible
I couldn’t push the hard plastic in any way as it is unmovable hard plastic.
Look in the pics at the moulded plastic that forms the side of the fridge to accommodate the shelves. 
I’m sure you do, d00d
Was the plastic protrusion on a lug and when you twisted it it loosened it and you could pull it out, releasing the glass so you could lift it out. Or twisted it upside down to a flat side.
l am not sure what a ‘lug’ is?
I couldn’t pull it straight out as the fridge door was in the way.
I had to get it out of the ‘wrong’ groove, over the protrusion that was not flexible but the edge of the glass wouldn’t budge over it…
I did twist it once l released it and straightened it. I had to use something to do this once l’d oiled the edge.
I am sure the repetition of my words must be getting painful for you all… so shall l tell you, or do you all still want to try and guess?
Please tell us.
A lug is - a projecting piece by which something is connected, supported, or lifted (looked up the proper definition in the dictionary).