Move commit head

If you want to move the current branch to point at the same commit as the target branch:

$ git reset COMMIT

Get file changes

If you want to get file changes from another branch without moving the current commit, you can do this:

$ git checkout COMMIT PATHS

e.g.

$ git checkout my-branch foo.py README.md

Note if you want to switch to another branch and away from the current one, you would omit that path.

e.g.

$ git checkout my-branch