Cut a hole on the bottom of the Altoids tin about from the end of the L to the end of the I. This is for the sensor. Use pliers to bend the sharp edges flat against the inside of the tin.
Cut another hole about 3/4" away from the left side. This is for the on/off switch.
Flip it over, and on the "A" end cut 3 tabs, bending the edges so that each can freely move.
Glue scraps of plastic so the tabs reach the 3 buttons. The 3rd one (in the middle) needs to be thicker or boosted with a glob of hot glue. I used old keyboard keys.
Tip: To make the glue dry fast, put it in the freezer for 1 minute and it'll be rock-hard.
Now take the board and align it with the holes and hot-glue it:
in the sides of the board's cutout,
beside the battery spot,
next to the silver oval,
and a lot near the cord for the sensor.
Now, glue the battery down and the contacts to the battery ONLY ON THE TOP OF THE POSITIVE CONTACT. If you glue the negative contact (spring) it will not connect.
