Heat the nozzle's temperature to 285 degrees Celsius for the heatblock to expand and grip it with a wrench.

Gently reattach the heatsink thread with your pliers, leaving some slack so that it is not flush with the heatblock.

Re-screw the cleaned nozzle but leave a gap between the nozzle and heatblock.

Screw the heatsink thread until it is flush with the heatblock.

Tighten the nozzle once again until you feel the that the nozzle's thread is touching the heatsink thread to ensure that filament does not build up in the heatblock threads.