In this solution you will learn how to replace the extruder assembly on an AXIOM single or dual Bowden Tube printer.
1. Turn off the power and unplug the printer then remove the back panel of the printer.
--
2. Locate the extruder assembly. 
--
3. Tape the 4 screw heads for the extruder assembly to the inner back panel to avoid the screws and spacers falling out of place.
--
4. Loosen the 4 screws but do not remove them, the nuts on the other side of the panel holding the extruder assembly in will come out. 
--
5. Remove the 4 nuts from the extruder assembly, 3 are highlighted in this picture but the 4th is in the lower left corner of the assembly.
--
6. Disconnect the stepper motor wire (on a single nozzle printer) or wires ( on a dual nozzle printer) from the RAMBo board.
--
7. Remove the extruder assembly from the screws, make sure to keep the spacers in place.
--
8. Unplug the USB A and B cables as well as the ethernet cable.
--
9. Install the new extruder assembly onto the screws and tighten the nuts to secure everything.
--
10. Connect the stepper motor wire (on a single nozzle printer) or the wires (on a dual nozzle printer) to the RAMBo board.
--
11. Install the USB A and B cables as well as the ethernet cable.
--
12. Test out the new extruder assembly.
--