Bulk Update Woocommerce Prices for all Orders in a particular Timespan

Hi guys,

from 07-01 until the end of the year, tax rates have been reduced by 2 percent in my country. Contrary to my assumption, the rate has not been updated with updating the plugins, and now 5 month later, i noticed the issue. Quite a few Order-Positions need to be recalculated now, with the order total needing to be the same but the tax rate needing to be reduced by 2 percent.
To solve the problem, I tried to simply edit the SQL order total tax, wich did not work, because before sending the E-Mail to the Customer, the order total is beeing recalculated from the order-positions data from wp_postmeta table. And even if that worked, the data positions data would not be correct, of course.

Does anyone have an idea on how i could write a Script, that does this Task for me?

Thank you very much!