To log in to the Office365 Web Access Client, open your web browser and go to portal.office.com website. Click on the "Sign In" button. Enter your Microsoft 365 email address and click Next. Then, type in your password and select Sign In. If prompted, complete multi-factor authentication (MFA) for added security. Once logged in, you’ll have access to all Office365 apps like Outlook, Word, Excel, and Teams through your browser. Bookmark the site for easy access in the future. Always log out after your session, especially on shared devices, to keep your account secure.