I think this thread has the best info:
http://986forum.com/forums/performance-technical-chat/42802-interior-vent-debris-3.html
Meir documented disassembly through the frunk in the first page and I later added the center console cut. It looks like Meir's .PDF links are dead now, but some of us have them saved if needed.
I have done 2 or 3 from the dash center console and one from the frunk when I was replacing the heater core. Both take a little patience, neither is terrible.