How would you trim these ikea door?

IKEA pax closets. The ceilings in this room are sagging towards the centre. The floors were levelled during renovation but we left the ceiling joists as is. It’s not noticeable to the naked eye.

However, these doors reach all the way up to the ceiling and the ends catch when opening. It’s very slightly, to the point that they clear the ceiling with no issues during winter, but during summer as things expand, they start to catch. You can see the marks on the ceiling in the 3rd pic.

I want to trim or sand them down at the top by ~2mm. Not sure what the best method would be without ruining the finish. I think a circular saw is not the right call… Sander? Any ideas are appreciated..