LINN 5140's - BACK to passive

I have LINN AV5140's that are in "aktiv" mode. I still have the original crossovers of course.

I took the bass driver out and unscrewed all 6 little nuts that were on the back of the plate (inside the speaker).... but I cannot get that plate and the 6 stems off to put the crossovers back in. Any ideas?