Step 1: Get Parts!
With a little creativity I'm sure you can substitute a lot of these parts for something similar.
2 AA Batteries
A holder for these batteries (see picture)
A small plastic container
A small steel ball or another ball that conducts electricity
Step 2: Burn Holes and attach battery
Insert batteries into the battery pack. Tape it to the bottom of the plastic lid and loop the wires through the holes. The positive wire from the battery pack (usually red) should stay on the top side of the plastic, while the negative wire (usually black) should loop through the second hole back to the side with the battery.
Using a tape measure, make a small mark on the edge of the lid about every 2.25 cm (But it will depend on the circumference of your lid and how many LEDs you have. To figure out how often to make a mark, do the following:
Circumference of the lid / Number of LEDs
This is purely aesthetic; if you don't care about your LEDs being evenly spaced or just want to eyeball it, the device will still work.