How do I copy blendspaces into a project?

I have several animation packs, so I have downloaded them all, exported them, and imported them back into another project so they all work with the same skeleton.

How do I do this for blendspaces? I just get the “Unknown extension t3d” error when I try to import them, or drag them into the content browser…

That didn’t take long. Inspiration struck.

I just copied and pasted in Windows. When I opened them inside the new project, I got asked which skeleton I would like them to apply to. I selected the Standard mannequin. Sorted.