With a handheld 2mm drill, clean out filament from the 2mm chamber
Hold nozzle in wise, use a gas torch or heat gun to heat up nozzle until filament is liquid, then use air hose to blow out grit
Expanding a 0,3mm nozzle to 0,5mm:
Drill press, wise, high quality print drill bits, drilling paste....and lots of fingerspitzgefühl!
Run the drill very slow, 100-150rpm
Ta-daaa..
This is high quality drill bits from Japan, got them from [
alfa-tech3d.com], 0,2 to 0,5mm, two of each
Erik