I've received a few questions about my grille so thought I'd do a write up on how I made it.
This is in no way 100% comprehensive, but I'll try to cover all the main steps that I followed.
The grille is compromised of a chrome plastic piece mated to a base plastic piece via 30 or so tabs in slots. I figured out from looking that at the factory they stick the chrome piece tabs through the base piece slots and then hit the back side with a soldering iron to melt the end of the tab so it swages out, kinda like a rivet made of plastic.
I used a dremel (probably the one tool I'd absolutely insist on having for this job) with a cutting wheel to cut the chrome ends of the tabs off on the backside of the grille. After all of them were cut off I carefully separated the chrome piece and the base plastic piece.