Q: how do i change admin?

If I understand your question, you want to create more than one Administrator account. As Administrator you can add a user account and give it Administrative privileges. Go to Settings>Users & Groups click on the lock icon and provide your Administrator password. Click on the + sign and add the account giving it the admin privileges that you want by checking the "Allow User To Administer This Computer"

After you create the account, to change from one to user to the other you simply log out of one and in to the other.