Step 4: Cut the Original Boards
Mark the original palm and wrist boards where you will cut them. On the palm board, ensure that your cut keeps intact all of the traces related to the bend sensors. On the wrist board, make sure that the cut keeps intact all of the traces that connect to the contacts for the D-Pad, Start, Select, A, and B buttons, and leaves ample room on these traces to solder new leads.
I've included photos of these boards with the cuts marked in pencil -- ensure you know where to make the cuts before you start cutting!
Now, cut the boards using a jeweler's saw, or your tool of choice. Remember that the cuts are small and precise, so if you aren't completely confident in the steadiness of your hands, it's probably better to use the saw than a power tool.