How to migrate cluster fileserver volume to another?

Hi there, 

This is what I need to do. 

I've setup file server under my win 2008 r2 cluster.  I have a volume Z assigned to it via ISCSI. 

The problem that I am running into now is that I have MBR on volume Z and I need to change it to GPT.
From what I was told, I need to bring up a new volume formatted as GPT. 

My question is how this could be done ?  Do I simply issue another iSCSI volume and format it as GPT, then copy or restore all the content to the new GPT volume, but how do I attach it to my file server cluster?  Do I remove the old volume Z and re-introduce the new GPT volume and driver Z and cluster will recognize it and use it , with all the proper permission etc ?  Because I remember isn't there some cluster disk signature that I need t worry about ?  

Thanks!