Log into Techsoup http://www.techsoup.org/
Click your name in the top right of the screen
Click "Validation Token"
Click "Microsoft for Nonprofits"
It will ask you for your Techsoup again, please login
Copy your validation token.
Click on the "Back to Microsoft Product Donations" button and paste your token in the token field to validate.
Confirm your organization.
You will see a message "Validation for (Your Organization) is being processed
Once you receive an email you may begin to sign up for office 365.
Click here if you have received your email and need to sign up.