Re: Bonnet badge change
It's an easy job!
As Jim says, take the shield off to get access to the pins on the back of the badge, which have spring clips on them which you'll have to prise off. The badge is also stuck to the chrome surround with double-sided tape. The best way to get that off is to use a thin, strong cord - nylon fishing line is ideal - & work it round to break the adhesion. The new badge comes with double-sided tape already in place - just remove the backing paper & stick the badge on - the pins will locate it for you.
I bought new clips for mine - not strictly necessary, but for around 50p each cheap insurance against the old ones not being reusable. Having said that, I don't think the clips are really needed - the adhesive does an adequate job.