Removing my callsign as a trustee for a club no longer active

I have been a trustee for a school amateur radio club that has since let the license expire as the school no longer exists.

The callsign expired last October but is in the 2-year grace period for renewal.

Doing a Google thing tells me I need to file a cancellation request with the FCC to remove the callsign from the system, which will remove me as trustee so that I can become the trustee of another callsign, since only one is allowed.

First off, is this accurate? If so, what form(s) do I need to fill out to file a cancellation request?

Thanks!