Step 1 :


Go to CMS - System Management - Public Users - Select the authors which you want to add or remove



Step 2 :


On right top there is three dots (click on that)



Step 3 :


 Under that you will find 2 options:-


1) Enable Show on Website and 

2) Disable Show on Website



1) Click on Enable Show on Website - if you want to show that author on front end (Website).



2) Click on Disable Show on Website - if you don't want to show that author on front end (Website).