I have a stock unrooted Droid X running a leaked version of the Gingerbread update (system version 4.5.588). How can I update to the official release (system version 4.5.596) without root?
There should be someone who has the official release that you can download and just upgrade like you did with the leaked version. Like this post here. It says it's for rooted users, but I don't see anything in the instructions that should require root.
You going to want to sbf your phone back to .340 first. Here is a great forum post showing how. I did it with my linux box, you can do it with windows but drivers can be an issue from what I have heard. Once you sbf your phone you can pull it down OTA. Warning this erases everything and you will loose root. The official release has not been rooted yet to my knowledge.
I have done it 2 times now I was running lexlite gingerade and sbf to install leaked gingerbread and then I sbf to install the offical release.
*Edit: * Looks like I was wrong it has been rooted there is just no easy root method. See @CaseyB post.
Let me know if you need any more help.