Here you go...
Purpose: OBD odometer correction for a Buick GL8 car
Tool used: Obdstar X300 DP
The dashboard shows the mileage: 447183
Go to Diag Program
Mileage adjustment-> GM
Obdstar x300 dp tablet GM V30.50 (newest)
Select the model: GM->Buick->GL8->Old GL8
Current mileage value: 447226km
Input the mileage of adjustment; here: 445000
comfirm
The new mileage value: 445166km
The dashboard displays the new mileage: 445156
OBD change mileage successfully!
Source:http://www.mileageprogrammer.com/x300-dp-adjustment-ok-on-buick-gl8/