Have you had that happen? It takes a bit of figuring to get it back together with the cool sliding mechanism designed for Stampin' Up! ink pads. The design allows the ink pads to be upside down when stored which keeps the surface of the pad moist.
I tried explaining how to put it back together again over the phone, but without a visual, it was pretty confusing. In the meantime, she wrapped it in plastic wrap. So, here it is. I hope it's helpful.
The pictures say more than I can. This first photo (figure #1) shows which ends to put together. The "outy part of the ink side goes into the inny part of the non-ink side" (I think that's about what I told my friend over the phone). Notice the sliding track where the "outy part" goes and that it goes in the end of the ink pad base that has the semicircle below the track.
In figure #2, I'm trying to show how you "walk" the other "outy part" forward to fit it into the track.
Then slide that second side back into the track while keeping the first side in its place as well (figure #3). Make sure you slide it as far as you can before trying to flip it back closed again.
Finally, you can flip the lid over to close it. (figure #4)
So, if you happen to have the Stampin' Up ink pads, this may one day be something that you have to do for yourself (you may have already done it). Just come back here and hopefully, these instructions will walk you through it.