Up near the top of the profile is a link for COMMENTS. If you post a comment on a profile, the manager will be notified. This is the best way to make contact, as other interested members may also see your comment and respond.
It's a good idea to first read through any other comments posted earlier to see if the changes you want to make have previously been brought up.
If you do edit the profile, it's also a good idea to make a comment saying that you've done so.