How to chnage the URL after a branch location change

[Jari Aalto]

An example

    bzr init-repo --trees project
    cd project
    bzr branch <URL> upstream
    bzr branch upstream local
    ... work
    ... then one day the original <URL> moves to another location

How do I make the 'upstream' to point to a new <URL> location for pull
operations?

Jari