How to achieve Löwdin transformation?

I use Gaussian 09 to obtain the Hamiltonian and overlap matrices, $H\_0$ and $S\_0,$ where the B3LYP functional and the 6-31G basis set are adopted. Then how to
transform the system to an orthogonal basis using Löwdin transformation?


$$
\begin{align}
H\_1 &= S\_0^{-\frac{1}{2}}H\_0S\_0^{-\frac{1}{2}} \\
H &= U^\dagger H\_1U
\end{align}
$$


