You need to know the Account Username and Password.
How to delete your Snapchat account
Go to the accounts portal and type in the username and password for the account you want to delete. (Keep this info handy in case you change your mind and want to reactivate your account.)
After taking the steps to delete your account, it will first be deactivated for 30 days. While your account is deactivated, your friends will not be able to contact or interact with you on Snapchat.
After 30 days, your account will be permanently deleted. This means that your account, account settings, friends, Snaps, Chats, Story, device data, and location data in our main user database will be deleted.
We may retain some personal data for certain legal, security, and business needs. For example, we’ll retain information about any purchases you may have made through Snapchat, and when you accepted our Terms of Service and Privacy Policy.
For more information, please refer to our Privacy Policy.
How to reactivate your Snapchat account
Want to reactivate your account? It’s easy! Just log back in to the Snapchat app with your usernamewithin 30 days of deactivating your account.
While your account is deactivated, you can only log in with your username and password. You can’t log in with your email address and you can’t change your password.
Please Note: It can sometimes take 24 hours before a deactivated account can be reactivated.