Looking at the Fiat eper, External Accessories, type plate, it looks like there is a single rubber bushing on the inside of the trunk holding that badge on, holding a pin on the back side of the badge. The pin on the back side of the badge should slip out of that bushing, but may be tight from old age. There may be some adhesive as well. Mine has the bushing inside. I can barely feel it with a finger, but the badge also feels like maybe it is glued as well, the pin used just for centering.
Unfortunately, the bushing is in behind the inside sheet metal. Try squirting in a little WD-40 behind the badge. Try prying gently, levering on the badge on two sides, not just one, as that just cocks the pin. Perhaps also try to rotate the badge at the same time to help free the pin from the bushing.
89 Milano (wife's daily driver since 1989, Shankle Sport)
91 164S (my daily driver since 1994)
94 164LS (~Q) (trip Alfa since 2000)
72 Morgan 27 (water time since 1976)
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6
Last edited by Del; 03-01-2017 at 10:50 PM.