How to send a message to S about a Nikon 10-30mm lens?

Does anybody know how to contact a user on YA?
"S" posted this question about a Nikkor lens with errors:

Since it went into voting I can't add anything to my answer, but it looks like there's a replacement lens available for £50 here:
http://www.digitalrev.com/product/nikon-1-nikkor-vr-10/MTEwMjc5Ng_A_A

How can I let S know?

You can send an email. Click on "email" at the bottom of the question box.

Click on the user ID under his avatar, Add to Contacts then use that in Y! Mail. If he doesn't want to be emailed by strangers then nothing else you can do.

Click on their icon.
Click on "View Profile"
Click on "Add Contact"
Go to "My Network"
Click on their icon.
If they have enabled email, you haven't, you can select "Email S"