Question [Q] How to change the Backup Pin/Pattern in Face Unlock

I have searched hard to find the answer to this question but was unable to get any.
I am using Face Unlock in my Moto G XT-1033 , and have trained it many times.
But now I need to change the pattern lock as one of my Friends saw the pattern
Is there any way to change the pattern without losing all the training that I have done ?