Instructions are simple, insert your CD or go to the folder where you have OCS R2 setup and re-run the setup. Click on Prepare Prepare Environment and then Create Enterprise Pool.
You will then face the same questions that you had to fill when you installed it. At some point the wizard will ask for the share folders location and you can change then.
Just make sure on the Reuse Existing Database page, clear the Replace existing database check box or else all your existing data will be lost (not good!).
Looks simple and effective but... it lacks some steps.
First you will need to go over to the Front End IIS and re-map all the virtual directories to the new shares. This one is easy to notice as you get alot of warnings soon enough.
Second, you will find this warning on event viewer:
Event ID 32020 Task Cat. (1055)
Unable to create the Application Host data directory.Oops... looks like something wasn't changed. :-)
Unable to create the directory \\ocs old shares\AppStore\Microsoft.Rtc.Applications.Acd. The network path was not found.
Cause: See error message.
Create the directory manually.
What i had to do to change it was (it might be another solution but i didn't found it):
Go to Start -> Run -> wbemtest
Click connect and type root\cimv2 and then connect.
Now, click on query and type this:
Select * from MSFT_SIPApplicationConfigSetting where Backend="sql_instance"
There will be a few instances returned but only one will have the DataLocation filled. You will have to change that to the new location.
And it's sorted.