Anyone know how to "tweak" speedo settings on a SCT9100?

[GeoffK]

Does anyone here know how to adjust the speedometer settings on a SCT9100 tune file? I know this is an older programmer but I am betting there is someone out there who has done this before. My speedo readout is currently off by around 6-7 mph. If I am showing 80mph on my speedo I am really going 73-74mph according to my GPS.

Thanks.
Geoff