piece of piss
take the little allen keys out at each end of the current radio
insert radio removal keys, or thin screwdrivers into holes to remove the exsiting radio…
Then its normally a torx bolt right at the back to remove so you can remove the old stereos cage.
What stero are you fitting in its place? – you’ll prob need to swap the perm, and switched lives over (the red, and yellow wires on the bak of teh new stereo’s wiring) to esnure the memory is kept when you take the keys out.
Just a case of chucking the cage in, bending the tabs in to ensure its secure, and slide the new one in….
Takes about 5 mins if you’ve done it before (and, yes, I used to work for halfords many years ago – and thought they now charge about 40 quid?)