1. Put your SD card into Rpi and snap the Rpi back into the shipping case. Close the case.
2. Align each external inputs (power supply, HDMI, USB, ethernet, etc) over the appropriate outlet on the outside of the case.
3. Trace the outline of each external input with a scoring tool or pen. Remove the Rpi from the case.
4. Use your hand rotary tool with a cutting bit and a grinding bit to remove the outline on the case until each external input can plug into its outlet.