Does anyone own the Icarus Films release EIGHT FILMS BY JEAN ROUCH?

[sabdo]

If so, then how in the name of all that is holy do you free discs three and four from their hubs without snapping or otherwise damaging them?

For those of you who don't have the release, the hubs I'm referring to are stiff circular protrusions surrounded by the clamps which hold the disc in place. Neither the circle nor the clamps give at all — you can't push the hubs down, and the only way to get the discs out seems to be to bend the disc. I don't see how to do that without breaking or warping the disc.

I've taken some photos but the files are too large to attach here. I hope my description is sufficient. Anyone know how to attack these stubborn hubs?