Go in Dimensions software (on each computer with our software) and log in as usual.
Go in the Configuration section.
Click on Taxes.
With the Left and Right arrows, select the province that you need to change and click on the Modify button.
Change taxes that needs to be changed according to the province standards. The checkbox named "Surtaxe" is only used it provincial taxes are calculated over the federal taxes (rare case).
Click then on the Save button to save the changes and after on the Stop button to get out of this window. Click again Stop (exit) et get back to main menu.