Lower the thermostat to the lowest temperature setting. Turn off the power to the Lennox Elite furnace and wait for the blower to stop operating before removing the access panels.
Place your fingers in the handle on the top access panel. Lift up the access panel with the handle to disengage the notches on the inside of the panel from the tab on the furnace opening. Pull it away from the furnace.
Grab the sides of the lower access panel with both hands. Lift up on the lower access panel, and pull it away from the furnace.
Turn off furnace and wait for cessation of blower, as in Step 1 for two-stage furnace.
Place your hands around the middle of each side of the front panel.
Lift up on the panel until it disengages from the furnace and pull it away from the unit. It might be necessary to rock the panel left to right to get both sides to disengage.