Decided to pull the Norcold frig out of our 1990 Spirit and have it repaired. "How tough could it be to remove" I asked myself. Pulled the door, perimeter screws, access plate from the bottom. Outside, make the gas and elec. disconnects. Labeled the wires. Pulled ground wire and screw from wood and flange mount. Still can't slide it out. What am I missing ?????