I'm attempting to remove the blower cover from the lower housing, but the cover seems stuck at the firewall just beyond the wheel well. What is the trick to removing this cover? So far, I've removed about 5 screws from the lower housing plus the motor that controls the fresh air off the bottom of the lower cover. I've pushed the black/green wire grommet through the housing, so no wires are holding things up. If looking straight on, with 12 o'clock on the firewall and 6 o'clock closest to the glove box, the lower cover is hanging at about 12:30 on the clock face. What is the trick to getting the cover to release in the back?