The noise in the background is the lasercutter. You can faintly hear the motor noise if you know what to listen for.
Find, test, fix and mount opto endstops.
Talk to Dieter about right screw for extruder.
Or go to RepRapSource.de/RepRap-Fab.org and buy a full extruder for ~€75 (without motor).
Mount extruder and go! :)