'Easy' is perhaps not the right word. It is not difficult but is can be a bit fiddly and time consuming. You need a selection of sockets and pliers. I have not changed a wing on a Cordoba, but on an old Corsa. I assume the basics remain the same:
Firstly, you need to locate all the bolts that hold the wing on, this involves taking the wheel arch liner out and looking with a torch for bolt heads that might be holding the wing on. Also open the drivers door, and in the gap between the door and the wing there are sometimes a couple there. You may need to loosen the headlight to check around there. DONT FORGET TO REMOVE THE INDICATOR or else you will rip it off and you'll have to solder the wires or glue the clips or something! Once the wing is loosened carefuly remove it (the door will need to be open) careful not to damage the car any further (I assume its been bumped!)
The new wing will need to be eased into place and the bolts tightened as necessary to ensure the panel gaps to the door and bonnet are even. replace indicator and possibly headlight if it needed to come off.
Hope this helps!!
Mr Smith
November 2008