I know what I'd try but I haven't got the slightest idea about whether it would actually work or not:
Install 7-Zip.
https://www.7-zip.org/
Create an otherwise empty folder and put the .tar file inside it.
Go to that location and right-click on the file.
Select 7-Zip > Extract here.
If 7-Zip can successfully unpack the .tar file, all of its component parts will then be inside the folder you created. (I'm unsure as to whether further work might be needed with those files to make them readable though).