Assemble N31L In the middle area, head back towards Polar Peak. On a Candy Cluster kiosk in front of the bridge leading to polar peak will be N31L's head. Pick it up and head back to the other side of the portal where you'll find N31L's body. Place his head on and he'll start right up. Complete the First Set of Challenges N31L will have a set of challenges that you must complete, each within a certain time limit. The meter at the top left will fill up as you complete them. Once full, go to him and interact with him to initiate the Knight Industries Two Thousand protocol.
Once activated, N31L will launch into the sky and return with an upgraded body and none other than David Ha**elhoff. The Hoff will then fight against zombies with you for about 3 minutes, however he's not too great at accuracy, so don't count on him to get you out a tough spot.
After Ha**elhoff's time is up, N31L will take him away and return, this time in need of an auxiliary battery. Auxiliary Battery Locations All locations are in the Kepler System portion of the map. In front of the Chromosphere on an Ice Cream kiosk On a bench near the DJ Desk location and Alligator trap Third location unknown Once you take the battery to N31L, the same process will begin. Do slightly harder challenges, initiate the protocol and receive David Ha**elhoff. Find the Floppy Disk All locations are in the underground area.
The floppy disk will always be on the edge of a table, tool chest, etc., so just search around until you find it.
For the last time, return to N31L and deliver the floppy disk. Begin the process again with harder challenges, protocol, and obtaining Ha**elhoff.
After N31L takes away Ha**elhoff, you'll be able to have him retrieved for $5000.