Yeah, it's in the help... but if you have never done it, I suggest getting assistance from someone who has the first time you do it, or at least read the docs and make sure you understand everything VERY thoroughly. There are things you need to do on the correct controller at the right time, and if they are done incorrectly, it can potentially be service impacting, even catastrophic, to other cluster elements.
For example, if you start sharing from the wrong element, all of your new controllers "blank" data could get pushed to all other elements via SDS, leaving you with a cluster of featureless devices.
Oh, and backup the entire cluster first... just in case you have to perform a restore on every network element.
It can happen, trust me...
