HStereo removal problems

[MarkP63]

I have just bought a CitiGo for my daughter. I was planning to replace the rather disappointing Stereo with a Blaupunkt one I have lying around but I cannot remove the existing one.

I have found some very useful instructions for removing the stereo, however I can't remove it as one the retainer clips which are part of the stereo and supposed to be released by the removal tools  will not disengage. The re.moval tool doesn't seem to want to go in far enough. The other one is fine

 

Does anyone have any suggestions, at the moment the only options seems to be to remove the central console and try accessing the stereo from below, or more drastically drilling the retainer.  

[stbb]

You have to take 4 screws out from behind heater panel then the removal tools will pull it out but mine was very very tight. Make sure remove tools are right way.