Re: Remove original radio?
I've never done this with an Alfa radio, but I've done the same for previous cars.
You don't necssarily need the special tools, but it does make the job a little easier (i've done it both ways in the past depending on how much I care about the radio I'm removing).
Using the tools means that you effectively have 2 'handles' to work with, rather than 4 bits of wire, which makes it easier to pull the radio away from the dash,whilst keeping the lateral pressure (towards the car doors) on the tools to hold the catches in.
Even using the tools, it is difficult to tell whether the catches are fully disengaged or not, and generally requires lots of rattling around, pushing and pulling, etc until it comes free.
Tools are available at Halfords, etc.