I wanted to share this process since it took me a while to navigate through documentation / support / etc to figure this out.
SnapCenter 4.0 RDM LUN provisioning is currenlty only accomplished with the PowerShell Commands.
This assumes you already have SnapCenter 4.0 Deployed
You already have added the Host to SnapCenter and Installed the Windows Plug-In
You need to log into the VM you want to provision the RDM LUNs.
I used PowerShell ISE where I could view the powershell commands for the SnapCenter Module as well as the SnapDrive Module (not really snapdrive, but that's what it is called).
Here is an example of what I would consider a simple and common RDM LUN Provisioning Operation:
new-sdstorage -storagesystem svm ip or hostname -path driveletter or ntfs mount point -LunPath /vol/volumename/lunname -size #andunit i.e.200G -igroup igroupname -Thin -RawDeviceMapping -Datastore RDM-Mapping Datastore Name in VMware -FileSystemLabel filesystemlablename -PartitionStyle MBR or GPT
Look through the other SDStorage commands for similar SnapDrive for Windows operations.