Here is the Flickr page explaining how to obtain the URL of your photos. You could bookmark it for easy reference.
Then enclose that URL with image tags and the photo will show up in the thread..
Then check with the [Preview] button and if everything is OK post with the [Submit] button.
That's the simplest way to do it.
And although a lower ISO setting would have been preferable if light conditions allow this amount of noise can easily be removed without any noticeable degradation of the photo. You should give it a try with whatever software you have available that is capable of NR. If you want I can show you how it would look on this photo.
When in doubt..... Press the shutter.