best way to upgrade wordpress blogs

I have about 60 Wordpress blogs that are using version 2.3 I want to upgrade to 2.6. I saw that a plugin that does all of the work is available but it automatically uses the newest version of wordpress - downloaded directly from wordpress. That will not work for me because the newest version is 2.7 but I want 2.6. I need an easy method to upgrade all of my blogs (this is not a MU version of wordpress). If you know of a plugin that will let me supply my own files that would be great. Also, I do not want my plugins updated in anyway. * back up DB * upgrade to the version of WP supplied by me * do not change plugins at all, if they have to be deactivated for the upgrade they should be re-activated automatically at the end. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows? (depending on the nature? of the deliverables): a)? For web sites or? other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software? installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform ..