Step 1:- Go to CMS - System Management - Public User
Step 2:- Click on “Merge Author”
Step 3:- Click on “Add” from the actions column which you want to merge
Step 4:- Select the author with which you want to merge the other author
Step 6:- Then click on the “Merge” Button
Result - All authors get merged with the selected author and all the articles will get also combined.