Changing the nozzle will most likely void the warranty.
In any case, the key is to heat the hotend to 165C+. TURN OFF THE MACHINE… to reduce the chance of shorting anything out (Mini or Taz 6). I use a 18mm wrench to hold the heater block steady, and a 7 or 8mm wrench to remove the nozzle. After the nozzle is loose, I like vise grips or locking forceps to remove it the rest of the way so it doesn’t fall on the PEI… the nozzle will be HOT. Install the new nozzle, I like to heat the hotend back uo to 165C to finger thread… don’t strip the heater block or nozzle. Heat nozzle to 240+ and snug the nozzle again… best to probably insulate the 18mm wrench with masking tape to prevent any shorts.
Here’s a more detailed post: