backup azure resource manager vm

Hi,

I'm trying to backup Virtual Machines created in Azure Resource Manager mode.
Only way that works for me is to make a copy of vhd os disk file of vm and later when I want to restore it I need to create new vm with vhd os disk file pointing to backup copy of vhd file.
Is there any easier way of doing this for example can I detach os disk from my original vm to replace it with backup copy of vhd(replace original vhd with backup)?
Or maybe you have other method to backup/snapshot/capture vm created in resource manager mode?

Thanks