The last time we touched upon LUN resigning, it was during an odd hour of the night. Looking back now, some interesting VMware KB articles have cropped up around this very topic.
First there is KB 9453805, which covers this process for VI3, seemingly from top to bottom, it also greatly expands on my post, by having you check the datastores view and remove the old LUN/datastore. Oh yeah, it provides instructions on how to do it from the VI Client, good stuff.
Next there is KB 1005751. This one covers much the same as the above, but from the service console, for those of you who are inclined to do it that way.
Finally, there is also KB 1011387, which covers how to handle this process in ESX(i) 4.
Now when bad things happen, you can be prepared! (Photo by: kait jarbeau )