Mount VHDX

Mount/Dismount VHD/VHDX with DISM

Mount dism /mount-image /imagefile:<full_path_to_vhd> /mountdir:<mount_path> /index=1

Dismount

Mount/Dismount VHD/VHDX with CMD

Mount

diskpart
select vdisk file="<full_path_to_vhd>"
attach vdisk

Dismount

diskpart
select vdisk file="<full_path_to_vhd>"
detach vdisk 

Mount/Dismount VHD/VHDX with PowerShell

Mount

Mount-VHD –Path "<full_path_to_vhd>"

Dismount

Dismount-VHD –Path "<full_path_to_vhd>"