I built mine per to the instructions that came in the box, but just didn't attach the shelves or the last piece of glass that would be the top of the cage, or the door of the display unit. I built them including the metal poles, which as far as I know aren't bad for the hamster, and actually come in useful for attaching water bottles and other things
)). If you are intending to use the lid, you would need the poles anyway for the lid to rest on.
Hope this helps, and enjoy your new cage!