I-Firefox Isithangami Sokwesekwa

I am looking for suggestions/work flows for migrating existing Mac's from the standard firefox release to the ESR version. I am looking to manage these all under 1 update cycle. A couple of current problems:

1. On a system with the standard version already installed, I can't find a way to upgrade to the ESR version without uninstalling first.
2. Once I would do an uninstall and then an install of the new version, I am prompted that I have launched an older version of Firefox and that I must create a new profile. How can I do this without loosing all users bookmarks, extensions, etc?

Thanks!