Geeetech

I simply cannot get the "left" extruder to unload and reload new filament. I added a roll of filament when I got the printer and now I want to change it but I can't. I can't from the device panel and I can't from G-codes.

I can change the Right Extruder only - that's not a problem - but the left one is impossible.

I warm up the "Nozzle" to 200 degrees (it is PLA) and I send the G-code "M600 T0" and "M600 T1" but only the actual extruder will unload.

you could set fire to the printer or you could use your hands (once temp is high enough), release and hold off tension (the tab next to the white tube) then gently pull on your filament with your other hand to get it out (also don't forget to reload another (really not a good idea tro work with only 1 installed)

in the menu, you scroll down to mixer and make sure mix is set to 100:0 instead of 0:100 for your let extruder (that way you'll be able to "pull" it out via the move axis menu)