-one safety switch, toggle or otherwise, with on/off (for convinience)
-a pringles can (can be one of the snack size or larger type, i cut down a larger type one)
-a camera flash circuit
-various bits of wire, in total not even a foot, but it's good to have extra.
-a motion/impact switch (i jerry rigged one up out of a grommet, a wire nail, and a bit of wire and solder)
-AA battery holder case thing
soldering iron or pencil
knife or scissors
pliers (or your hands, doesn't really matter)
Step 1: Remove circuit, attach safety
Once you have your circuit discharged, you can begin work.
First switch is the safety switch.
Take your toggle switch and one end of the battery holder, preferrably the forked end (+ end) and solder one contact of the switch onto it by a bit of wire. then, attach the other contact to your battery ( i don't know how smart or dumb this was, as i soldered it in place.) The battery didn't do anything to me, it didn't explode, but in hindsight, i assume this was an unsafe decision. Attach the battery to the wire with elecrical tape or solder a proper battery holder to the original contacts. This creates a safety switch which allows you to cut off power to the grenade so it doesn't accidentally charge and go off, as these circuits are finnicky.
Now take your knife and cut out a hole in the side of your container to fit the switch out the side.