I'll try and keep it brief.
Undo clip the side trim panel by the driver door and remove.
Undo the screw.
Unclip the trim that covers the steering column.
Unclip the trim by the clock (this one is a right ****er to get out, so take your time)
Remove the 4 bolts holding down the centre console, they have plastic covers on them.
Lift it slightly; unclip the power connector for the cig lighter.
Then lift the centre console out. It can be tricky, push the gear stick out of the way and pull the handbrake all the way up.
Undo the push pins and clip holding in the gear stick surround trim, and pull it back towards you. When you have some space to get your hands in, pull off the silver trim around the gearstick (this gives you more manoeuvering space).
Remove this trim piece.
You're now left with the radio - there are bolts (2) underneath and screws on the top. Undo these and it just pulls out.
Undo connectors and remove radio.
Connect up the wiring loom to the car connectors.
Install the new fasica panel.
Connect up the radio connectors to the loom through the fascia (make sure all the wires go through the fascia hole...) and route the cables for the reverse camera down the back of the unit so they are accessible underneath.
Install the radio into the fasica once all is connected up. Depending on what radio you've got, it can be a bit tight!
Install the reverse camera - not sure on this one myself as I've not done it but I do remember seeing a guide here.
Once done and you've tested the radio, fit the trim panels back in reverse order.
If you get stuck drop me a PM mate I'll try and answer any and all questions - I needed help to install mine and so am more than willing to help out anyone that needs it