Major repairs for Lego Titanic!

[solveliver]

I completed the Titanic build, all 9090 pieces. It took many months...

And then...  a random drunken event, I crashed into it and smashed the back of the ship!

This picture shows the damage to the back of the ship. It is built in sections, the red dotted line is where this final section attaches.

However, I cannot separate this section so I can rebuild it... Can anyone help? I have a PDF of the build instructions, which doesn't not seem to include picture-based steps for this crucial step. And I dont want to be heavy handed and cause more damage! There are no obvious pieces holding the sections together. And I can't recall how it joined previously. I wonder if it snapped into place?

I can't upload bigger file sizes, but can provide them somehow(?!) if anyone can respond to the thread.