All you have to do is go to where your factory is, and go directly under the floor. After that, disconnect from the server and relaunch it. You should be transported up into your floor after a brief time.

Please be aware that I glitched myself off perpously and did this just to ensure this was a full proof method, and it reset my factory before I started mass producing items. A lot of time lost.

And yes, you can easlily glitch through the walls by spaming jump and/or crouch, do not try it.
Best of luck