XYZ DaVinci 3D Printer constantly jamming
The clicking sound typically means the drive gears are slipping on the filament because there is a jam in the head/nozzle.
First thing to do is clear the nozzle. You can use a small drill bit to clear the chamber, but if the extrusion hole (at the tip) is clogged, you'll need to get a set of fine wires designed for extruder clearing.  Then heat the head above melting point and slip the wire in (if possible).   

In general, I find it easier and faster to replace clogged nozzles.  They're cheap, and more often than not clearing the exit hole enlarges the diameter (bad thing).