Step 7: Done!
Well, hopefully anyway. Put the battery back in your laptop, try out your new plug, and see if you get power. You might have to fiddle with the length of the rod, or smooth out the surface of the magnet/epoxy combo. If you're not getting power, try testing the continuity between some of the washers on the plug, and the ground point on the laptop. If there's a good connection between those, then the problem must be the rod/post connection, so check on that. Make sure to clean the surfaces off so there's no grease getting in the way.
Enjoy your new freedom to trip over your power cord!