Re: New bonnet badge for 156
Right! Turns out the boot badge was the simpler of the two to replace!
The badge has a little plastic shaft that on the back sticks through the lock and is secured inside the boot with a spring, a fat white washer and then a small retaining ring. It's fiddly but once you've unscrewed the boot lining and peeled it back, you can get in there with your hands and remove the retaining ring and then slide it back on when the new badge is in place. No need to drill out the screws that hold the lock in place and remove the whole assembly, as I've seen other people suggest elsewhere! If you do happen to drop some parts down inside the boot door (as I did, because it's a pretty awkward space to work in) then slamming the boot shut gets them to fall back out.
Took me about twenty minutes in total. If I can post photos later I will.
As for the front, I decided that the best way to remove the glue holding the old badge was to drill a small hole in the chrome grill surround and fill the space behind it with a solvent (I used vodka, in the absence of anything else!). Then used a heat gun to soften it up further. Dropped off in a few minutes this way.