Hyper-V: Exporting VM with only 1 of 2 VHDs?

Hello,

A Windows 2012 server has a Windows 2012 VM with two VHDs: a primary 800 GB VHD and a secondary 4 TB VHD that is used for archive data.  I need to Export so I can then do a spin up restore test before major updates are applied to the original VM.  But when going through the Export wizard, it errors out because both VHDs are fixed and there is not enough space to hold 4.8 TB.

So is there a way to export only the primary 800 GB VHD (short of removing it from the VM config and adding it back)?  Does a product like Altaro allow for granular VHD back up options?

Thanks!