Strange shower door.

[JohnLaw]

My shower door has rollers on the top but the bottom doesn't ride in a track. The bottom of the outer door has a U shaped flange on the bottom that grips the base of the enclosure from underneath. The inner door has a larger U shaped flange that grips the flange on the outer door. I don't know how to get these doors off without unscrewing the flanges from the bottom of the doors. It looks like this:

i=inner door
o=outer door
b=base


i.....o
i.....o..bbbbb
i.....o..b..o..b
i.....ooooo.i.b
iiiiiiiiiiiiiiiiiiiiii.b
.................b

The drawing didn't work too well because spaces get lost.but I think you can get the idea.
I replaced the spaces with dots.