Last week I withnessed the un-mounting of my ICS, by an Alfa-mecanic.
He did the job in +/- 30 minutes + many curses. The most time consuming part was, indeed, the springs.
These side clips are a kind of small leave springs. When you unmount the black plastic surround (like niallmoran says) they are hidden behind the upper
plastic surrounding, which you did not remove. I even could not see them with a torch. It is a trick ( you have to feel it) to press them with a small screwdriver, towards the ICS. While doing that, you have to try to move the ICS back and forth. If it moves a bit, the spring is pressed in (already @ 1 side) . Now the other one.
: when you take the ICS out , know that the cables are too short
to take it out completely.
Then, be careful with the noumeours connectors. They all have a kind of clips, which you have to press in, before removing . Especially the one @ the bottom, which is mounted upside down
: the clips is not easy to reach (do it with a screwdriver) .
Last but not least : when my ICS was unmounted, 1 spring broke off. Acc. to the mecanic, no big deal, since the ICS body is really fitting very precisely into the holder.
That's it, it theory
Life is easy, isn't it ?