I have a ge refrigerator model # "tbx24jabrrww" (a 24 cubic foot fridge about 10 years old freezer on top) I need to know how to access the drainage pipe to the evaporation tray so that I can unclog it and stop the leakage of water inside the fridge

Remove panel inside back of freezer. Drain is more than likely full of ice. Use hot water to unclog. Will be messy.