Swapping new model with old without upsetting keyframes

I have imported a CAD-based file and started animating it.

However, the client now wants to use a different model with the same animation.

So what is the best way to swap out the file without destroying the keyframed animation?

Maybe parenting and hiding old from rendering!

If your new model is in Blender (even in another scene) you simply exchange the mesh of your old object with the mesh of the new object. You do that in mesh panel be clicking the mesh icon next to the meshes name.

Hint: Ensure you have meaningful mesh names, that you can easily identify the right mesh data block. I usually find it hard to find the right mesh when everything is called Cube.??? ;).