How to become someone's sponsor when they are already sponsored

[Jim Meyering]

Richard W.M. Jones wrote:
> Jim Meyering (FAS username: meyering) was sponsored by Warren Togami.
> It seems that Jim can no longer set the fedora-review flag on packages
> that he's reviewed, and this may be connected with Warren leaving Red
> Hat for new pastures yesterday.  In any case I've agreed with Jim that
> I'll become his sponsor.
>
> *However* there is a problem ...  I can see no way to change the
> sponsor of an existing packager in FAS.
>
> How do we go about this?

Thanks Rich,

Background details: this arose because I have reviewed and just
tried to set "fedora-review = +" on this RR:

    http://bugzilla.redhat.com/570627

and now all I get is the big red failure notice:

    You tried to grant fedora-review. Only a user with the required
    permissions may make this change.