Are there any good tools for account management?


I am using accounts-password, accounts-twitter, paccounts-facebook in my *

Now I consider to move my app to other PaaS.
I want to keep my users using their data and I did backup the data.

Transfering the data to new database seems easy, but When I move the site, I think that I must change OAuth app tokens and reset user tokens.

How can I do that? Are there any goo tools to transfer user data to new database?