How can I restart the smart card service since OSX Yosmite without rebooting?

Do you know what the process is for the Crypto Token Kit? Most likely, the answer would be similar to the one you linked, i.e. kill it and then restart it. The only thing is that any startup arguments may have changed.

I used to do something similar at times in that I would kill pscd to clear a situation, but I don't recall ever having to start it manually. I believe it either came back to life itself after a few moments or perhaps I triggered it by unplugging the smart card reader and then plugging it back in.

I would suggest trying to kill the process first and give it a minute or re-plug the reader. If that doesn't work, let us know?