This is a step by step guideline on how to convert a Hyper-V image to Sunlight.
Hyper-V (vhdx) to Sunlight image conversion
Install an ubuntu 18.04 VM on the Sunlight platform
Run the following commands (as sudo user)
apt-get update apt-get install qemu-utils
Download the raw (.vhdx) image to convert and run the appropriate qemu-img convert cmdline
qemu-img convert -f vhdx -O qcow2 <image>.vhdx <image>.qcow2
Insert the converted output image (.qcow2) into the Sunlight template manager.
Sometimes the relevant drivers are required in order to obtain maximum performance or to achieve full compatibility with the Sunlight platform.