Open the file in Inkscape, select the image that you want. Copy it (control c) open a new inkscape file using the menu of the open file, then paste (control v) the image into the new file.
You might need to ungroup the original image first, but not with the file you are showing. Also, Ink has a really quirky memory for copy and paste, and you have to use documents opened from the source file to paste between documents, you can't just open a new one from your start menu or desktop.