Taking panels off Hotpoint Mistral Plus?

I have a Mistral Plus dating back 8 or 9 years. It was left in a house without electricity but full of food and was colonised by some nasty bugs. We've cleaned the interior of the fridge and freezer compartments, and the freezer will descend to -20 or so without any problem, but the fridge remains at +20 or so without cooling at all.
I'm guessing that these insects - which left LOTS of maggots and eggs behind - also colonised the pipe between the freezer and the fridge and blocked it.
So, how can I get to this pipe? I've removed every screw I can find and have removed the top, doors, back of the freezer compartment and control panel at the top, but can't make the side panels budge. I'd thought they were like side panels on a computer and would slide off, but they don't.
Any help or hints would be MUCH appreciated.
Thankyou.