any help please

 

This will save me writing it out. This guy isn't removing his stereo, but several pictures down you'll see how it's held in. it's actually screwed into a cage like holder. He does show you how to get to it though.

How To: Flat Black Interior (work in progress) - IWSTI.com: Subaru STI Forums

 

The FAQ in the ICE section is probably your best bet.