Welcome to Prime!
While I only had Steve Ghent replace ball joints on the rear, I believe that the front uprights have to be removed completely so the old ball joints can be pressed out and his new ones installed.
I would probably wait and do them all (both sides) at once, when you can handle a bit of NSX down time.
Hope that helps (front pair in the upper part of photo);
<a href="https://picasaweb.google.com/lh/photo/NoqImSKVtHIsytcPgarGhzbyA_2VUxXf3QgO-KOYIRE?feat=embedwebsite"><img src="https://lh4.googleusercontent.com/-GKpcuYaGmFM/U9pFCKrBXvI/AAAAAAAAAKI/prBCdXISzZA/s800/Ghent%2520Ball%2520Joints.JPG" height="600" width="800" /></a>
Brian