We are talking about the electrified 8x10processor? Hard to imagine it is damaged, this is all very simple mechanics. There is the processor, make sure to keep everything clean, you have to inspect and wipe the rollers after each use. Then there is the tray that will be attached to the processor and the Land Film Holder which just slides into the tray from the front side. There is no problem to do this with the tray removed from the processor. Maybe it is a little bit stuck from not being used a long time but you should be able to just slide it back. It will probably be easier to help pushing it a bit from the dark slide side (blue). Don´t press the top and bottom side as this will prevent the movement. My model is one of the latest, the Film Holder says Model 81-06 and the tray is engraved 81-09 both made in UK.
It will probably be not easy to get good full developed results now but the images have always been dreamlike. This "sensor size" is probably the only thing I miss with todays technology. Hope this helps, have fun and good luck to get this going!
Cheers,
Ulf