The Exchange databases are pretty simple.
Present the new storage from the new SAN. Stop all the Exchange services, and move the mailbox files from the old disks to the new disks. Remove the old disks from Windows, and change the drive letters of the new disks, so that they match the old disks. Make them cluster resources. Start the Exchange Services.
For the Quorum that’s a bit harder. Attach the new Quorum to the server with a different drive letter and make it a cluster resource. Edit the cluster from the Cluster Admin tool. You can change the drive which is used as the Quorum. You can not remove the old Quorum from the cluster and remove it’s drive letter.
If you want quorum to have the same drive letter as before, the safest way to do that would be to repeat the process with a second new LUN from the SAN. This time using the correct drive letter for the new LUN.