I've got this pink bike that nobody uses but I like the gears. On the left (or by the petals of bike) it's got 3 gears and on the right (by the back wheel) it's got 7. on MY bike it only has 5 gears on the right and I want to swap them out. Is there a way that I can take off the sprockets so I can swap them? If not please answer my question so I know.:D