This is probably the trickiest part of the dis-assembly of the Hemma Cord Set -- as it requires that we break part of the inner plastic connections in order to release the socket components.
In the accompanying photo, you'll see an inner bushing that has tabs on each side (in the upper left quadrant of the photo).
The method that worked for me was using some pliers (wrapped with tape to protect the plastic) to twist the top of the socket until those tabs snapped. Work delicately & slowly here. Too much force will damage the outer plastic.
Once the tabs snap, you'll see that the interior bushing twists freely (shown in the lower-right quadrant of the photo).
After the tabs have snapped, you'll be able to simply unscrew the top cap that is holding the remaining socket components to the wire (lower-left quadrant of the photo).