Welcome to the forum.
It may be required to replace the entire fixture.
When I needed to service the head sink faucet in my 2000 380DA, I removed the door below the sink. I also removed the interior panel in that compartment to gain marginally acceptable access.
Here is an example of a replacement fixture. Flounder Pounder Marine has other options in stock.
https://www.fpmarine.com/Scandvik-plumbing-fixtures-p/46009-scandvik-new.htm
If other items are preventing acceptable access, then removing / replacing those parts is probably also required.
