Use a Swept Base of two concentric circles and a path, or better, use a Swept Base with the circle that creates the body, and a Swept Cut with the smaller circle and the same path as before.
Make 3 sketches, I made two sketches on the top plane, each one has a circle in it. And one sketch on the front plane containing a spline.
Click on Swept Boss, choose the sketch that contains the larger circle then the sketch that contains the spline.
Now click on Swept Cut, choose the sketch that contains the smaller circle then choose the sketch that contains the spline again
And you're done.