[RichLockyer]

They have both an online calculator and a downloadable one that'll give you the exact parameters to program the unit.

Mine is the older one, so for a 70/78 error, the programming procedure would be:

Total error: +11.4%
Correction factor: -10.3% ( don't know why the difference)
SH Calibration Value to be stored: -10.3%
SH Conversion mode Value to be stored: 0

- the ignition must be OFF
- set ALL SH switches ON
- turn ON the ignition
- press the button => memory cleared

- set ALL switches OFF EXCEPT #4
- press the button 1 time(s)

- set #6 switch ON
- set #4 switch OFF
- press the button 3 time(s)

- set #6 switch OFF => all data stored in Flash

The newer unit is actually easier to program. On mine, the various switches represent the "places" in the correction factor. Switch #4 is the "tens", switch #5 is the "ones", and switch #6 is the "tenths"... so I would set switch 4 and press the button once to set a "1" in the 10's place.
Switch 5 is left at "0", and the 10ths place is set to "3".