I can't get to the menu. It seems to require the remote. All the button on the TV does is brings up tv channel scan and demo.If it's not fixable with geometry settings in the menu then you're going to have to access the service menu.
Sony Trinitron 27XBR45 is the TV.
Edit: Turns out my Sony HDTV remote operates it, insane! There's no settings to adjust the slanted screen. How do I get into the service menu? I assume I'll need the original remote, which I ordered.
Here's a picture. You can see the upper sides go inwards.