If your Z-belt is broken or needs replacing, here is a guide on how to swap out the belt.
One side of the x-rods will be glued to the sliders, one side will not. Hold the slider in one hand, and the x-rack in the other.
While holding the slider and X Rack, gently pull apart from each other. Please be careful as to not bend the Z Rods, only a small gap is needed.
Rotate the slider so the pegs point upwards. The X Axis is now free from the sliders.
Take the print head and begin to slide it off the x-rack towards the end that is free to remove from rack. Set print head aside.
Next, push down on a corner of the base and pull up on the same corner of the lid to remove the lid (see picture below for technique)
With the lid removed, you will see the z-belt running around the four pulleys on each threaded rod in the corners. Take a hook tool to grab the belt and slip it up and over the plastic base of the printer.
Pull the belt up and over the other corners of the printer and remove
Take new belt and put it around all four threaded rods
Pull down the belt around the plastic edges of the printer and replace belt on all four pulleys
Double check belt is not flipped upside down
Take lid and replace it, aligning all rods into their respective holes
Replace print head onto the x-rack
Your printer is now ready for use again
Please recalibrate the bed location before printing