Having had lots of experience with nozzle clogs of all types, If its clogged with filament, remove any filament in the extruder or Bowden tube, heat it up to 250 for PLA or 270 for ABS, then let the filament flow out, once it stops, while its hot unscrew the assembly with gloves and a spanner. Then leave it to cool.
Once its cool, soak the heater block, PEEK, and nozzle in diluted caustic soda for PLA or acetone for ABS.
If its a non filament blockage, heat the nozzle as described and find a needle that will fit inside the nozzle tip. Be very careful when pushing out the blockage as to not damage the nozzle or to burn yourself. Then unscrew the nozzle while hot and clean out the heater block and nozzle with the same solvant solution. Hopefully that should remove the blockage.
After removing the blockage, clean everything with meths and leave it to dry, when putting it back together, you may need to extrude some filament to fully clean the nozzle insides of any remaining meths or solvants
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