The process was to first use a bandsaw to cut off the very bottom of the shoe's sole. This was easier on the sandal because it was pretty much a straight line cut. The tennis shoe cut was far more difficult due to the compound curves of the shoe. Cutting rubber stinks!
I glued 1" layers of balsa wood together to achieve the desired height, 6" on the sandals and 4" on the tennis shoes. I traced the outline of the sole on the balsa wood block and used a bandsaw to cut the profile. A stationary sander was used to fine tune the profile.
I then profiled the top of the balsa wood block to fit the shoe's curvature. The bottom of the block also had to be profiled to her specific walking pattern. Again, the tennis shoe profile was much more complicated than that of the sandals.
The top of the shoe was glued to the top of the block and the sole I had cut off was glued to the bottom of the block.
The balsa wood is so light that the shoes' weight changed very little. The girl needed longer arm crutches due to the added height.
The smile of the girl's face was ample reward for the work.