So I finally got round to changing my front badge and decided to post what I did for anyone who wants to do this on their car. I believe the 159 will be the same.
There are lots of posts on here that say what you do but I never found any pics besides before and after which is why I am posting this with steps to make it as clear as possible for people who don't normally do diy on their car (like me!).
Hammer, Nail, Long Pliers, Cloth/Rag, Bug Spray (just because it was handy).
(Click Here For Images
First gently tap the nail into the badge below the center and continue to do so until you make a hole big enough to get long nose pliers through. Then use the pliers to twist the old badge and remove. I also used a cloth to protect the rim from any damage.
Then I cleaned up with Autobrite 'Just the Tonic' Bug & Tar remover (Hopefully I will get paid for advertising.....) and removed any backing tape left so the surface was clean.
Before going straight into fixing the new badge put it on without removing the tape cover to check it sat right and was happy I would be able to put it on straight first time. The replacement badge I got had a protective cover over the face so I lifted this off the edges which allowed me to put the badge on and then easily remove the cover after.
Job done! Took about 10mins (removing sticky residue takes up most of that time)