This method won't work on my Granamyr due to the length of the actual four clips and how they were molded, no matter how many time I've tired pushing the right arm into the socket or heat the socket and the clips inward! The design and the plastic material of the joints weren't a good choice for this figure, that's why some of us have problems in different areas of the figure, at least that's my own humble opinion... The only solution to fix mine is to glue the shoulder's rod into the ring joint, or of course take the risk and send him back and wait, hoping for Mattel to send me a flawless figure...
Sorry to hear it, I still have a few days before I receive mine and all I can be is hopeful.
I just started collecting MOTUC in Nov 2012 and just trying to play catch up.
I read that article this morning and thought it might help some.