You can terminate your Wickr Me account from within the app. You will have to be able to login to the app in order to delete your account, and there is no way to delete an account without the current working password.
On mobile devices, you can go to Wickr Menu -> Support -> Terminate Account.
On Windows and macOS, you'll tap the menu next to your avatar, and then select Support -> Terminate Account.
To delete your Wickr Pro account, please send the request to firstname.lastname@example.org