inverse the direction of the Z motor

[Lepterois]

Hi!
I changed today my Z scew on my Ormerod2.
But now the direction of the scew is inverted, and as a newbie, I don't know witch Gcode I've to put in my config.g. Actually in my config.g, I've M569 P0 S0 to set the X axis direction, I guess that the same for Z but I didn't find M569 in the wikicode.... and I don't know what is the number of Z motor? Is it P2?
As well how to adjust in the config.g the step/mm for my Z?

Thanks in advance

[Lepterois]

OK I found to reverse.... M569 P2 S0
Still to adjust the step/mm