Updating core modules independently of core?
For example, could you update Views without updating core?


First of all, you should check if you could get away with implementing those changes via a hook, event subscriber, or altering/overriding a service.



If not, download Lastest_Drupal_8.zip and unzip only /core/modules/views folder onto your projects /core/modules/views folder.

If you like, you could create a patch for that particular core module using git diff between latest and current version.

Although, I wouldn't recommend to do this to begin with, this is bad practice!, but if there is a really, really, and I mean, really good reason sure. 

Caveats:


You'll have to test the core module to make sure all is good.
You won't be able to use composer update unless you find a way to make it run the patch.