in car radio

Obtain the appropriate removal tools for your stereo, from your local Car Audio store, or from an online store.

Insert them into the holes, and pull out your stereo.

Disconnect the two ISO plugs and the arial lead from the rear.

Remove the metal cage.

Insert the metal cage for your new stereo.

Connect the two ISO plugs and the arial lead to the rear.

Push new stereo into cage.

That's it - the whole job takes about 2 minutes. If you have no ISO plugs (unlikely), or a non-standard DIN-opening in your dash, you may need to spend a few quid on adaptors - again, your local Car Audio store can supply these.

ISTR that Felicia's used Blaupunkt RCs but will need a facia adaptor as it wasn't quite standard din sized, but not the full moulded in fitting like the Fabia.

Might not be quite so easy, I think this is where VW got involved, and used slightly non standard sized steroes from Blaupunkt.