Hi Tom
There should be Pix in another thread, However from an oral point of view , here goes
The ECU is underneath the fuses, Right hand side looking from the front. It is a flat rectangular black thing.
On its right hand side you should see two very small allen screws which hold a cover plate over the USB connection.
Very easy to lose the screws so have a cloth underneath when undoing.
Cover plate is maybe 1 inch by 1/2 inch.
Hope this helps
