i've been asked this many times so i'm using the opportunity with my sons custom rattler to show how this is done.
this MUCH easier to do with the tiger force rattler vs. the blue rattler. the tiger force rattler plastic is softer and the glue bonds are not as difficult to get around.
just incase someone has not had a tiger force rattler, you can take the rear tail fins off by pulling down on the back end of them. pull toward the front and down and they snap out easily. you can see the small tab that lock them in place in this picture
nothing really special here