Splitting 2 partitions on a single VMDK to 2 VMDKs

Hi All

Due to a configuration oversight when creating the VMs, I have inherited four Server 2012 VMs which have a Single vDISK which in turn contains a C: drive (OS) and D: drive (Data/Files). The first 80GB is the C: drive, the remaining XX TB is the D: drive.

For ease of future managibility, I want to split these two partitions into individual vDisks.

The VMs (vDisks) are thin provisioned and reside on a Starwind iSCSI LUN.

What is the easiest way to do this?

My end goal is the following:
1. Split C: into vDisk 1

2. Split D: into vDisk 2

3. Reclaim any unused space (Thin provisioning)

At first, I was going to treat the vms like any other system (make a backup with shadowprotect or similar, then restore C: into the first vDisk, and D: onto the second), but is there a better, faster way to do this?

Any help appreciated.