Thought I would share with you how this went..
I used _The_Editor_ instructions from this thread http://www.alfaowner.com/Forum/alfa-...badges-11.html
1. Apply wax to new badges, leave on bench in garage to dry.
2. Drill small hole through the old badge, directly in the center - I used a 3.5mm HSS bit. There's a recess behind the center of the front badge that the drill bit punches into so that's no trouble, but no space behind the rear one. Go slowly at the back and stop drilling as soon as you're through the metal and dipping into the plastic underside.
3. Use a small flathead screwdriver (I used an electricians one) to gently prise the metal badge away from the rest of the badge support. Careful not to dig the screwdriver into the car!
4. Once it was reasonably free, I used some thin needlenose pliers to work around loosening off the old badge/adhesive until the badge peeled away.
5. Clean up the adhesive - I used a craft knife blade to remove the worst of it, then some acetone on a rag to soften up the remnants and wiped clean.
6. Once surface is clean and dry, buff off the wax from the new badges on the bench, remove the adhesive backing paper, align the metal tab at the bottom, and stick it on!
I used a brand new 5mm drill bit and a old school hand drill for control.
Took some pictures along the way.
Glue came off with a combination of G101 All purpose cleaner and IPA then the residue with a microfribre and friction to get it all off.
The rear glue literally just pulled off with no help and just wiped down with IPA and dried so it sticks better.
As with the _The_Editor_ s intructions do go crazy on the rear one as you will just drill into the backing plate.
They look spot on are identical to the original as far as I can tell even down to the locating tab and the sticky pad used.
Hope _The_Editor_ doesnt mind this, all credit goes to him.