What are you using to edit it. If you are calling the editor from the command line you can prepend it with "sudo". E.g.
sudo vi /usr/local/bin/bzr
If you aren't editing from the command line then I would copy the file to a location where you can save it and the copy it back from the command line using
sudo cp localfile /usr/loccal/bin/bzr
I assume you are an administrator on your computer. If you're not none of this is going to work.
What are you using to edit it. If you are calling the editor from the command line you can prepend it with "sudo". E.g.
sudo vi /usr/local/bin/bzr
If you aren't editing from the command line then I would copy the file to a location where you can save it and the copy it back from the command line using
sudo cp localfile /usr/loccal/bin/bzr
I assume you are an administrator on your computer. If you're not none of this is going to work.