how to move optimised media

Hi everybody,
I'm still stuck in the process of optimising/creating proxy file from my original media, for reason well explained in this post...optimised media - x2pro - avchd...how can I tell FCPX to point to the optimised ones not to the original media?

Now I have a sub-problem which I need to fix hoping in the priceless help of this community..

I had an 1/2 Library (mostly original media) on a 3T thunderbolt disk...in this optimisation/proxy process the disk got full...in the inspector, I pointed a new folder for media in another disk (a 2T 800 firewire disk). Of course, the optimised/proxy file are being written there when generated...again this is happening for the files FCPX is stil generating.

At the same time, for a matter of performance, I need to put my 3T thunderbolt disk back in its previous status (empty space+ the 1/2T library).

At this point the question is: if I move the optimised media folder from the 3T thunderbolt drive to another drive....should I have to relink these moved files? And if yes, how? In order not to have to generated them again.

Is there any other process than simply copying and moving folders? I read something somewhere about using event manager but I didn't really understand it.

Thank you in advance for your help and patient,

Nico