Reset Password with Token

Hi Guys

I'm putting a proposal together to get our website to start using Tokens instead of clear text passwords in the Send Credentials email.  It all seems pretty straight forward to create a link in the email that will include the token.

Using this token I can login using the web API but I was wondering once you have logged in how you can update the current password.  If you don't know the password and you only have a token how do you update the current password.

The only methods I can see are UpdateLogin and UpdateLoginWithPromoCode and they require you to know the existing passwords.  So not sure how to do this.  Not sure if this is possible with the current SOAP API without creating a custom method.

How are you guys doing this?

Thanks

Nick