Hi LesJ,
https://www.youtube.com/watch?v=F_FroFtJz1cChoose your registration.(J button if I am not wrong)
Press save.
Rename your registration as "Empty" and save it as a NEW registration.
Now you have two similar registrations with diferrent names.
To the "Empty" reg press edit and delete all registrations from 1-8
Save again the registration.
Make the changes you want and save again as NEW registration.
I think is better to keep this "Empty" registration so you can easilly create new ones.
Before you try anything first save your registration both to user and usb folders to make sure that if you make a mistake you will not loose your first registration.