This Instructable is for removal and replacement of the small plastic joint holding Barbie's arms on.
Step 1: Parts & Stuff
Thread lock or solder + iron
Step 2: Arm & Body Prep
There are two plastic nibs inside Barbie's chest cavity. Push them in until they fall out, and shake her around until you get them out. If you don't do this, they will rattle around inside her.
Step 3: Replacement Joint Fabrication
After you have the screw the right length, get to work on the nut.
Place the nut in a vice and grind it until it is more or less shaped like the head of the screw.