My first approach would be to use Disk2VHD
on each VM running in the VMware environment. Manually creating the VM and attaching the vhdx in Hyper-v would be fairly easy. Be sure to power down the VMware version before starting the Hyper-V version.
There is one gotcha to be on the look out for. I recommend uninstalling any sort of VMware guest integration before creating the vhdx. I ran into a problem years ago when I converted a VMware Workstation VM to another format and the VMware Tools would not uninstall from the new guest because the uninstaller was trying to access the VMware host components via a private API and the whole install failed when the API call failed.