I made a file mysql-init.txt and saved it in C:\Users\Barry.
The file contains this.
ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';
I stopped MySQL server from services.msc
I then ran this from a command prompt
C:\Users\Barry>mysqld --defaults-file="C:\\ProgramData\\MySQL\\MySQL Server 8.0\my.ini" --init-file="C:\\users\\barry\\mysql-init.txt"
I then opened another command prompt, and logged into mysql with -uroot -pMyNewPass
I terminated the Command Prompt that started MySQL with the change by Ctrl+C
I started the MySQL service and then Workbench required MyNewPass for root to login.
Once logged in, I changed my root password back to what it should be.
So. The process in the refman works for me. Follow the steps exactly.
Good luck,
Barry.