To remove or replace the workbench on a GTX rolling system is not difficult and you may need to do this if you want to swap the benchtop over of if you want to access the key locking system to replace or repair the locking system.
You first need remove 1 to 2 rows of drawers as the 12 mounting bolts are attached from under the benchtop and you access them from the drawer spaces.
You will need a large phillips head screwdriver to loosen or tighten these bolts. The video here starts with both the top and drawers removed so you can see where the mounting holes are located. There are 6 mounting holes at the front and another 6 at the rear of the bench.
Looking from below you can see where the bolts are pushed up through those mounting holes and are then screwed into the benchtop, you just need to remove enough drawers to give you the space for your tools.