Here's the link to the spreadsheet:
https://docs.google.com/spreadsheets/d/1VI6QfLjBRydlyyDmMevjQ01GqApEfBSUnES4mGyRKH4/edit?usp=sharing
You can add your info to the group spreadsheet on your desktop, laptop, or mobile device. On a computer, you should be able to click the link and go. Feel free to use a google account and save the sheet to your drive. On your mobile devices you will need to download the Google Drive AND Google Sheets apps.

The only place you should be entering information is the "Weigh In" tab. You only need to enter your "The Challenger" username, "Current weight" in pounds, and "Challenge Weight Loss Goal" (the number of pounds you want to lose during this challenge, not your weight goal). Please leave the "ID" and "Class" columns alone. If you find errors in the spreadsheet, please contact SingRunTing rather than fixing them yourself.

The "Weigh In" tab in the group spreadsheet is accessible and can be edited by everyone. All other tabs in the spreadsheet, including progress sheet, are protected and semi-automated. The spreadsheet is prepared in a way that it just need your input in the "Weigh In" tab. The spreadsheet will be sorted alphabetically just once after 6 pm (Eastern time), January 11. ID numbers will be assigned at that point. Any late editions will be added to the bottom.

After the first milestone (January 20th) your goals will be locked and the only information you will need to update for the remainder of the challenge is the "Current Weight" column in the "Weigh In" tab.

See the FAQ post for more details.