How can I put wheels on this? I have googled and googled and I can't seem to find a way to wheel it and make it roll.

[Kanekoded]

I'd frame the entire bottom in with 2x4's using brackets to attach the base poles to the frame. Then, I'd attach 4 heavy duty retractable workbench caster wheels - two on the front and two on the back. After which, I'd tie a rope handle as a pull to the front portion of the wood frame.