Critter Nation 162 Question

[Essentia]

I had two chins come into the rescue today with a Critter Nation 162 with the 163 add on. With my other 3 story cages I have the bottom shelf removed and the wheels directly into the cage. With this new "snap together" model, I can't figure out a way to attach the wheels unless the shelf is attached to the bottom. Anyone able to do this with the new models? If so, I need advice!

 

[smhluvsmh]

You have to use the shelf.

 

[smhluvsmh]

Have to use the shelf if you want to use the wheels!