I have a GE refrigerator model-GSL25JFXJLB. The water dispenser line is freezing up behind freezer door liner. I can use a hair dryer to thaw for a quick fix. I bought a recess heater part#WR51X353 but it did not come with instructions. I don't see any screws to pull the freezer liner. It appears sealed. How do I get in there to install heater?