You don't need to deactivate your account to change your username or kit url. You can change it on the settings page.
A Kit user can irretrievably delete their account This will remove all their kits, comments, and recommendations on the site. A former kit.co user can always sign up for a new account in the future if they wish, but it will be a brand new account: nothing from a pre-existing account will be carried over.
Before you deactivate your account, please note:
Your account should be removed from Kit within a few minutes but some content may be visible on kit.co for a few days after deactivation.
We have no control over content indexed by search engines like Google.
The steps to delete your account are:
Log into your kit account.
Scroll to the bottom section labeled "Danger Zone"
Click "Delete your account"
If you have any other questions, please mail firstname.lastname@example.org