In the photos here, I am replacing the small bust of the 48cm with the Obitsu 50cm large bust (predictable). I will also be swapping out the head and the stock abdomen vinyl with the Yamato VMF50 Type B part. The abdomen replacement procedure is not yet included in this tutorial.
The first step is to remove the head. From the back of the head, grasp the head firmly just above the neck. Avoiding touching the face area! While twisting back and forth, pull the head up away from the body.
If you grasped the head firmly enough, the neck piece should come off with the head, without dislodging. If the neck piece has become dislodged from the head, see the New Obitsu Neck Piece tutorial also in this forum.
Next, remove the arms. Grasp the doll by the center of the chest, squeezing the soft vinyl till you can feel the hard skeletal structures underneath. While you have a firm grip on the “chest bones”, rotate the arm and pull straight out away from the arm socket. Repeat the procedure for the other arm.
Now the bust should slip up and off of the skeletal parts. Before placing the new bust on, inspect the spinal part’s integrity and “zero out” the many joints in the spine. All this amounts to is straightening and aligning these parts, which can become misaligned from use. Pay special attention to straightening out the arm sockets and their many joints.
It is worth mentioning that while you have the bust vinyl off, take a good look at the many joints in the arm/shoulder/neck area. With a resin doll, you can see exactly where the two parts of a joint meet, whereas many Obitsu joints are hidden inside the soft vinyl. In order to make full use of these joints while posing the doll it is very helpful to know where these joints are and how they pivot. Since you can't see the actual joints, it is good to know where you can hold the skeleton by feel through the vinyl to operate these joints without stressing them.
Once you have inspected the visible skeleton, slip the new bust piece (in this case the Obitsu 50cm large bust) over the skeleton. The abdomen vinyl should fit nearly in side of the bottom of the bust piece.
Next, replace the arms. Make sure the internal arm sockets are squarely visible through the holes in the vinyl. Again, rotate the arm as you insert it. Repeat the procedure for the other arm. You may have to move the bust piece around till the internal socket is aligned with the hole in the vinyl.
Finally, replace the head. First, look in the top of the neck and verify that the neck attachment part is centered and pointing straight up towards the top of the neck. If it isn’t you can squeeze the neck and move the attachment to adjust it.
Then grasp the head and neck piece assembly and fit the neck piece into the top of the vinyl. Gently push the head/neck piece down till it encounters the neck attachment. You might have to wiggle the neck piece around a little to get it to seat properly on the attachment. Once you feel the connection is made you can push the head/neck piece down the rest of the way.
