Remove the following five secrews/standoffs from the DC-to-DC board:

One 3 mm Phillips in the lower right corner.

Two 3.5 mm Phillips on either side of the battery contacts.

One 10 mm Phillips in the upper right corner.

One 14 mm long 4 mm standoff in the upper left corner. You can remove this standoff either with a 4 mm nut driver or needlenose pliers.