Despite being able to see the resistor pack from outside, it needs to come out through the interior. Go in through the passenger-side door, look under the dash, and you’ll see something like this. The plastic beauty panel is retained by four hex-head screws. Don’t break your panel during removal; but even if you do, it won’t affect the operation of the heater or A/C. It is there to make the heater look better and kill some of the interior noise. Once you’ve got the beauty panel off, you’ll see the resistor pack behind it; it is easily removed with two screws.