Put a 0.0005" indicator and magnetic base on the machine table. Put the tip  of the indicator on the bottom of the toolholder. Set the indicator to 0.
Slide the magnetic base toward the spindle. Do not let anything touch the tip  of the indicator.
Remove the toolholder from the umbrella tool changer pocket.
Put the toolholder into the spindle.
Record the MACHINE Z Position value .
Multiply the MACHINE Z Position value by the value in Parameter 33 Z RATIO (STEPS/UNIT).
In this example the value of Parameter 33 Z RATIO (STEPS/UNIT) is 554872 .
(Z position value) x (Z Ratio) = Calculated value
-0.0093 x 554872 = -5160
Change Setting 7 to OFF.
If the calculated value is negative, add the absolute value to Parameter 64 . If the calculated value is positive, subtract the value from Parameter 64 .
Push 5% RAPID, ZERO RETURN, Z, then HOME G28.
The Z Axis moves to the tool change height. If the tool change height is correct, the indicator goes back to zero.
If the indicator does not go back to zero, do this procedure again.
Change Setting 7 to ON.