Ok, so I came to a harsh realization. Below is a picture of this thing:
Note the verbiage:
It is kind of a trick GMAT question really. Since you have to load the roll on the right first you can conclude that the roll on the left that constantly gets replaced is not being rotated. For good measure I decided to go through with the plan though, but it proved very difficult. This thing doesn't actually come apart at all, it is designed to be sealed so I guess it is shielded from splatter and such. Everything has to be done from the bottom access. To make this more convenient for the custodian it slides off the wall very easily so you can flip it like so.
I had to pull out the one roll in order to slide the divider over to access the larger roll to mark it.
The larger roll is so damn tight in there I couldn't pull it out, another reason to believe this roll is there to stay forever. You can see where I stuck the sharpie in there and made a mark. Yes, that is blood where I cut myself from trying to yank the fucker out.
The other side marked for good measure:
You can clearly see one of the marks through the translucent plastic.
And to cap the old times...