Sceptic, just lay the negative, emulsion side up (shiny side down) on the glass, within the 120 scanning area, and scan. Move it over and scan again, so you've scanned the entire negative in two passes. Now use the Automate|Photomerge command to stitch them together.
That's all I can really say on this forum, but it should be enough.
The Crown is really no substitute for a true view camera like a monorail or field camera, but it does have a small bit of movement and works well even if the rangefinder is busted like mine.