Migrate users from ASP.NET Membership Database

If you want the process to be completely transparent for the end-users (no password resets) then the recommendation would be to leverage a database connection with migration enabled. This would imply that end-user would be migrated to Auth0 (while maintaining their current password) upon the first login operation; this would require that the current infra-structure (or at least a trimmed down version of it) would be kept in place until all end-users are migrated (which would be roughly equivalent to all end-user having performed at least one login).