Changing map on an existing server

[Natas 4]

Simple question. Is it possible to change islands or whole grids on a running server without a complete wipe?
I edited servergrid.json to change one island but this is still the old one.
Deleting ocean files hasnt worked, looks like everything is stored in the database after the first start.
Someone knows free tool to access the database?

[Natas 4]

I could solve the problem by deleting the wrong island, changing the atlas id.
Then I started the server without this island (island disapeared correctly).
After that I inserted the new island again, changed the atlas, started the server again.
Now is the island on the correct location.

While this trial and error.  I figured out, that deleting the ocean file is not needed when adding new islands.

Looks like all structures, creatures and anchored ships are stored in the ocean files.
Players, Tribes, ships on sea are in the database.