1-Have the ir sensor high enough so it's not triggered.
2-Get the hotend to operating temp.
3-Lower the hotend until the ir sensor triggers.
4-Set Z to 0 using G92 Z0.
5-Then lower the hotend until a piece of paper slightly drags, and use the new z position on the LCD or via M114 for the z probe offset. If you have the EEPROM enabled, don't forget to update it.
The X & Y offsets don't have to be accurate.
2-Get the hotend to operating temp.
3-Lower the hotend until the ir sensor triggers.
4-Set Z to 0 using G92 Z0.
5-Then lower the hotend until a piece of paper slightly drags, and use the new z position on the LCD or via M114 for the z probe offset. If you have the EEPROM enabled, don't forget to update it.
The X & Y offsets don't have to be accurate.