Changing nozzle

I have read different posts here and other places, on changing the nozzle head. I have a new one I want to put on, however, I cannot free u the existing nozzle. I have tried it while hot, warm, cool, etc. To no avail. I do not want to break the head, so I am leary to go any further. It’s a Taz 6. Ideas??

I use a 7mm open end wrench and a 18 or 19mm wrench to hold the heater block that the nozzle threads into. The nozzle only has 2 flat sides so you have to use an open end wrench and not a box end as the box end won’t fit. I heat up the extruder from 200 to 230 degrees Celsius, then TURN OFF THE PRINTER (you may cause damage if you put something metal or wet on the nozzle while its powered on). Once off I put the new nozzle on until its snug, heat up the extruder to about 260 degrees Celsius and give it a little tug on the tightness. I think its supposed to be about 30 in. lbs but since I couldn’t get a socket on it I never could use my torque wrench :frowning:. Remember right is tight and left is loose.