Start in the upper corners then pull the string (not too thick) down the sides so the string ends up behind the outer edge of the panel. Tie the ends to form a loop. Join the two loops together to form a handle and pulls the loops inwards to stop them slipping off then pull. You can get string down to the bottom but may have to use a saw action to get it there.
There is a bit of slack in the connectors. Obviously to remove the panel the connectors will need to be removed.
Do you understand how I am telling you to get the string down the vertical outer sides of the climate panel. Look at the replacement panel you have. you can see on the left and right edge there is a step between the main body of the climate and the larger rear of the front panel. This is the area the string fits against to pull the unit out. Wear gloves to protect your hands.
Modifying your picture by adding a blue line where the string has to be fed through the rear of the panel face plate.
View attachment 73025
String is held at the upper end, pushed into the top right corner then pulled down the outer edge until at the bottom. Repeat for other side,
Take a picture showing the whole of the front of the installed climate and I'll draw on it where the string enters and exits on each vertical side.
The blue lines show the final positions of the loose ends that you tie together to form loops then tie to make a handle. The red broken lines is where the string enters from the front as you pull it down the edges...
View attachment 73029
Seems stuck fast, need more force, have you got a soft grip sash clamp like this?
View attachment 73027
Several suggestions how to use.
Not having a double din dash I am not exactly sure if this is feasible. First if you are not too fussed about the climate I tighten the clamp on the unit would get real hold of it like this and really pull. Better if you have two clamps.
View attachment 73030
Andy
Pity, these type of clamps I find indispensible for DIY about the house.I might have tried this if I had anything like this however I don’t, and don’t know anyone who does unfortunately...
So you end up with the two ends of each string tied together to form loops and those loops joined by another loop.
View attachment 73031
I have removed 2 panels using this method.