Below are the commands to copy file from and to containers using kubectl commands. Remember even if you are using windows containers you will still need the linux paths to make it work.
Copy FROM CONTAINER to LOCAL and the format of the command is
kubectl cp NAMESPACE/PODNAME:/tmp/foo.txt ./foo.txt
kubectl cp i-install/i-install-7445ffb8df-jshk9:sites/web/web.config ./temp.txt
Copy FROM LOCAL to CONTAINER and the format of the command is
kubectl cp /tmp/foo.txt NAMESPACE/PODNAME:/tmp/foo.txt
kubectl cp ./temp.txt i-install/i-install-7445ffb8df-jshk9:sites/web/web.config