Migrate different author’s content to current author

This can be done easily via dashboard.

Firstly check how many users you have in the database by going to Users --> All users and delete those users whom you don’t in the database by clicking on delete user.

In the next step you get an option whether to delete all the content owned by the user(going to be deleted) or to attribute all the content to some other user, so in this phase select the user you want(current user).Do the same for all the users.