This is based on code originally written by Richard L. Lynch https://www.richlynch.com/2009/11/18/permanently-pair-wiimotewii-balance-board/
Compile or download the .exe from the release page.
Run the .exe follow the instructions. You may need the "Microsoft Visual C++ Redistributable for Visual Studio 2017" which you can download from the bottom of the page here: [https://go.microsoft.com/fwlink/?LinkId=746572]