Hi bayleyspop
In order to install the door gasket properly you have to remove the door from the cabinet, place it on a horizontal flat surface and then remove the old gasket and install the new one.
The screws should be tightened in the following order: the first screw - at any corner, the second screw - at the diagonal corner, the third screw - next corner from the second one and the last one - at the diagonal corner. All other screws could be tightened in any order.
- For future references here are the break down diagrams for the GE refrigerator
Model TBX18DGBR
Good luck.
Gene.