How to extract auto archive for migration?

Ok, probably a dumb question here.
I just tested the auto Migrate to just grab some older installs from c9 before it goes away.
I downloaded the tar file and extracted it no problem. But then it just has either a .full or .home file that won’t open with anything and wont’ extract (using 7-zip).
Am i missing something here or is there a proper way to extract the .full or .home files from the auto migration?