Step 2 - Fill in the name and email address, then select Next. We'd recommend sending the password to the user's primary email address as well as to your own.
Step 3 - Assign the appropriate Office 365 License, then click Next. Note: If you don't have any licenses available, you can still add a user and buy additional licenses later.
Step 4 - Decide whether you'd like this user to have administrator privileges, and add any relevant profile information. Click Next once done.
Step 5 - Review information and click Finish adding.
Step 6 - Click Close.
For more information, you can find Microsoft's guide on this process here.
Edit existing User
Step 1 - Click on the Display Name of the User in question.
Step 2 - Click the blue Manage link next to the information that needs to be updated.
For more information on updating a username or email address, you can view Microsoft's guide.
Delete user Step 1 - Select the checkbox next to the user in question, then click Delete user.
Step 2 - Select Delete user.
Step 3 - Select Close.
For more information, you can find Microsoft's guide on this process here.