Step 5: Put on a flat and drill some holes
Somehow, either using a file or grinder or anything else, flatten out one side of the rod.
I was feeling all fancy, so I used a mill. This just makes it easier to drill into.
Now, find a tap drill for an 8-32 screw and drill two holes in the coupling, about 1/4" from either end.
May I suggest the tune "Fake Palindromes" by Andrew Bird for this step?