It is like a lightbulb fitting (only with a spring clip)
When you look at the underside of the bonnet you will see a clip around the badge base. Use some pliers and twist it, you will find that it just falls away allowing you to remove the base unit from above.
To fit the new unit, i found it easier to set the spring clip almost at the locked position and drop the whole unit in from above, this leaves you only with a half twist on the clip to do to lock it in.
Think of it as a lightbulb fitting, and it will fall into place easier than this post reads!!!!!
In any case better than the (i think) £95+VAT the dealer wanted to do it!!
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