How to De-provision Users?
The De-provision Users feature allows you to manage users, it contains several useful options for admins to use before removing an user account from Office 365 tenant.

When someone leaves the organization, it is important to make sure that you secure all the confidential data and files. Organization would never allow the user to retain the sensitive information. De-provisioning an user improperly, can result in data loss and security breaches.
Perform the following steps to De-provision Users:
Select Office 365 Manager from the available vertical tabs. Then from left side of the application, select Manage Users and Groups category and then click on De-provision Users.
On selecting "De-provision Users", a pop - up window is displayed as shown below:
 

     

     
  • Select the desired user(s) and Click on OK button to display the respective user details.

     
  • Select options from the list displayed to perform on removing the users from Office 365 tenant.
     
  • Reset user password option can be used to reset the password for the selected account. When a user leaves, the first thing you want to do is reset the password on their account, so that they can no longer access their account. Resetting their password means you can still access their mailbox but prevents them from accessing sensitive information once they have left.
     
    Once you reset their password, auto-generated password will be sent to the selected e-mail addresses.

    You may use Make this user change their password when they first sign in option to prompt user to change their password, next time they login.  
  • Remove access from user mobile device option can be used to remove mobile device access for the configured users from Office 365. If there are mobile devices connected to Office 365, you can either ask the employee to remove this on their mobile devices or, if the employee has been terminated under unfavorable circumstances, you may need to remotely wipe their mobile devices to prevent them from accessing corporate data or information from the device.
  • Remove licenses assigned for the user option can be used to remove all the Office 365 licenses / services assigned for the user.
  • Replace user account with another account option can be used to replace user account with another account in Office 365. When a user leaves, you can rename the leaver’s account with the new account.
     
    If you want to replace additional details for the selected users, click Additional Details..., then the window will be displayed as shown below:  
     
  • Archive user OneDrive content option can be used to export the OneDrive folders and files for the selected users from Office 365. OneDrive for Business is a bundle that comes with Office 365 used for storing and organising your work related documents. All the files that you store on OneDrive for Business are private unless you share them, so when employee leaves your organisation, you should check to see if there are any documents to archive before deleting the user account.
     
    Click View documents to view the OneDrive documents for that selected user. OneDrive document viewer window will be displayed as shown below:  
     
  • Copy exchange role permissions option can be used to copy role permissions from the selected de-provision user to another user automatically. When a user leaves, you may want to automatically copy role permissions from one user to another user.
     
  • Copy administrator roles option can be used to copy admin roles from the selected de-provision user to another user automatically. When a user leaves, you may want to automatically copy roles from one user to another user.
     
  • Copy group membership option can be used to add the group membership of the selected de-provision user to another user automatically. When a user leaves, you may want to automatically group membership from one user to another user.
     
  • Remove email forwarding option can be used to remove forwarding address which you have already configured for the selected mailbox.
  • Forward user incoming emails to another mailbox option can be used to forward all your incoming emails to another mailbox automatically. When a user leaves, you may want to automatically forward the user new incoming emails to another mailbox.
    If you want to forward all your incoming emails to another mailbox, then click on users and enter the valid e-mail address to forward incoming mails.  
     
  • Convert user mailbox to shared mailbox option can be used to convert an user mailbox to a shared mailbox. Office 365 allows you to have any number of shared mailboxes. These mailboxes do not require a license. The mailboxes have all the same functions of a regular mailbox. The shared mailbox has a storage limit of 10 GB. Once the user mailbox is converted to a shared mailbox, you can remove the license from the user account, freeing up the license for use with another user.
  • Remove user from groups option is used to remove a specific user from all groups the user belongs, so that the user can no longer access any information related to the groups.
  • Remove user from exchange role permissions option can be used to remove a specific user from all the exchange roles assigned for that user.
  • Remove user from administrator roles option can be used to remove a specific user from all the administrator roles assigned for that user.
  • Restrict user access option can be used to prevent the selected user to sign-in to Office 365.
  • Delete user account option can be used to delete the selected user account from Office 365 tenant. Deleting the user account also frees the Office 365 license assigned to that user. When you delete a user account, you don’t lose their data and the user becomes inactive. The user’s data is stored for 30 days, the user account and all associated data can be restored.
Once you have selected the options to perform on de-provisioning users, click on Apply button to run the de-provision task.