LOL. OK..
Radio out.
Disconnect all wires.
Cage in and push some tabs up down and sideways. Pull wires through at the same time so you don't lose them.
Connect wires to the radio - make sure it all works.
Push any blocks/fuses/spare wire into the gaps around the IP/under the cage.
Push radio back - you might get some resistance the last few mm's.. if it's any more than that, pull it out and see what's causing the issue. Torch/fingers .. try not to lose too many knuckles on the cage.
Repeat until it clicks in.
If you're near Basildon Essex, I'll sort it out for you.