(1) Go to the auto parts section of a major chain store like Menards or Fleet Farm. Buy a tub of grease. The best choice would be labeled as being for Marine applications.

(2) Apply grease to threads of cog. Screw cog on side of hub with the two tiered threading.

(3) Walk your bike down a big hill and ride up.

(4) Apply grease to threads of lock-ring. Screw lock-ring on smaller threads (counter clock wise). Get it on tight. Use the special tool. If you don't have one, a pipe wrench works pretty well. Don't have a pipe wrench? Put the end of a screw driver in one of the notches and tap the handle of the scew driver with a hammer. In all cases, you will need to brace the wheel against a wall or something to hold it still.