On this diagram of your ice maker, diagram 7 Replacement parts for FRG NGS23ZZAB1 | AppliancePartsPros.com you can see the bracket on the side. It hangs on screws in your freezer wall. Your old one will lift off the the bracket when you loosen the screws. There may be another one at the bottom. Then you can unplug the wiring harness. Cord has four round female connectors, comes with an adapter that will convert it to three round female and one round male connectors.

I installed the ice maker without any problems, but it doesn't seem to be making ice fast enough. I didn't use the adaptor cord that came with the new unit. I simply connected the cord on the new icemaker directly into the cord in the back on the freezer.

Did I do something wrong?

The temperature is approximately 10 degrees. Normally, ice is produced 2-3 every hour. The bar is moving up and down, but since I installed it yesterday, it has only made about 6-12 ice cubes.