Phantom 20 restoration

[Phantom 20SG]

Fellow boaters, I am in the midst of restoring a Phantom 20, complete tear down inspect and rebuild.

While removing the ballast system I reached transom sea cock/drain valve which I have NO CLUE how it is mounted to the transom.

Can someone share their thoughts/expertise on how to remove the drain valve from the transom for inspection and refurbishment. Attached is a picture of what I am referring to.

Many thanks in advance

 

[Phantom21-250]

These are not fun to remove you need to be able to turn the fitting from the outside of the boat and unscrew it as the fitting inside the boat isn’t able to turn, but that’s easier said than done.
Ideally leave it alone unless replacing transom it’s a bit easier to get at. If you can serviceit in place!