I just replaced my icemaker in the SubZero 532. It

Turn the Freezer and icemaker off. There are two screws pointing up holding the shelf above the icemaker down. Take them out and gently push the front of the shelf up to see the plastic tube coming out the back wall that the metal tube pushes onto. You will probably need to thaw the excess ice out first. Push the metal tube into place over the plastic tube it should curve toward the icemaker cup. Don't push it on too far or it will miss the cup.

the metal fill hose should fit into a rubber fitting ..at the back of the freezer...