With the clip removed and the windshield out, it wasn't too bad. Stand inside on the floor board, lean out the w/s opening to help jockey the outer case in place.

You don't state a/c or w/o/a/c

I cannot speak for a/c, but if you want to supercharge the fan-air flow on woac, this is a have-to-modify while you have the heater box out.

The 'warp' had completely obstructed air flow. I already started wallowing it out with a heat gun before the photo session, lot better than when I started. Even if it's not warped, if you amputate the shown area, it makes straight-shot, mass-air flow, rather than the 180' transition.

Before the modification, it blew ZERO air, fan motor ran fine, absolutely freeze your [censored] off lamf! Now, @ highway speed, I can open the heat flap, and plenty of hot air will drift in without the fan with 32' ambient temperature. I run a 160' thermostat, not a cabin heat thermostat as recommended by the book, but the 160' thermostat it's plenty enough heat for my winter climate, @ 16' it keeps you warm. If I ran a 190' (cabin heat) thermostat, the additional 30' of engine heat, and the fan, and it would roast you out of the car.