I am having trouble right now with the same problem (finding Ixx and Iyy).
\begin{equation}
I_{yy} = \int(x^2 + z^2)dm
\end{equation}
where
\begin{equation}
dm = \frac{2M}{R^2 + H^2} q dq
\end{equation}
and q is my generalized coordinate that is measured from the origin down the length of the...