You can promote a user to Moderator as long as you are Group Administrator.
You can access a user to Moderator of a group. Group moderators have permission to write in the group, delete messages, mark highlights, view and kick users.
To promote a user to moderator follow these steps:
- Access the list of members throught the option See group members.
- Find the user you want to promote to moderator
- Select the user and in the list of options select the Promote user to moderator
From that moment the user will have moderation permissions.