There are 8 of those hanging things because they are planetary symbols - see the symbols on the round metals.
1. Look at the middle bar
a.- Enter the present zodiac sign. It is September so the Zodiac sign now is Virgo. Scroll the bottom arrows that are on the sides of the middle bar until the Virgo sign is seen (one that looks like M with a curve going inward at the end).
Now enter the first letters of the months that Virgo sign fall on. So it will be August to September -- A and S. Scroll using the upper arrows of the middle panel until you get A, S.
2. Since now is September, the 9th month - IX. Use the bottom or top icons for the planets to bring all the round metal with the planet icons aligned to the IX on the side bars.
3. Pull the lever on the right and if correctly done, see the planets at the center of the park outside move and align.