How to change your Office 365 password
Login to your Office 365 account or Outlook Web Access (OWA)
www.office.com or outlook.office365.com/OWA
Sign in with your school or work account. e.g. (name@domain.tld)
.
Settings
> Password
Change your password
Is the option to change your password missing or not working ?
This could be due to your organisation disabling this feature to prevent you from changing it.
If so, contact your support representative for assistance.