All I had to do to convert my M1530 running Ubuntu over was use the cp command:
mkdir /mnt/root && mount root_partition /mnt/root mount /dev/sda1 /mnt/target cp -a /mnt/root/ /mnt/target/
You might also have to repeat for other partitions like boot and home. cp -a is awesome. It does exactly what you need for this process. Now my computer runs perfectly (other than me having to tweak grub a little for the right boot options). The only issue is you will have to move the contents of /mnt/target/root in this case to /mnt/target after this is done, as there’s an issue with dotfiles being copied in the root directory of the source.